The M&A Closing Cost Breakdown 2024-2026: Legal, Tax, QofE, R&W, Advisor at $5M to $500M EV

1. Quick Answer

We benchmarked M&A all-in closing costs as a percentage of enterprise value across the $5 million to $500 million EV range for 2024-2026 transactions, synthesizing the BTI Consulting Group Premium Rate Survey, the ABA M&A Committee 2025 Private Target Deal Points Study, the SRS Acquiom 2025 Deal Terms Study, Big 4 deal advisory practice guidance, Bain, McKinsey, and BCG M&A reports, and SEC EDGAR transaction-cost disclosures. Three top-line findings follow.

First, all-in closing costs decline with deal size on a power-law curve: approximately 12% of EV at $5 million (about $600,000 combined), 8.3% at $25 million, 7% at $50 million, 5.9% at $100 million, 4.5% at $250 million, and 3.6% at $500 million. The widely repeated 1% rule is materially wrong for lower-middle-market and middle-market transactions and is approximately correct only at $5 billion or larger EV. Pitchbook recorded $410.7 billion in US PE middle-market deal value in 2025 across approximately 4,018 transactions per the Pitchbook 2025 Annual US PE Middle Market Report, which sets the population this benchmark applies to.

Second, the five major cost categories in descending order of magnitude are: investment bank and M&A advisor success fees (approximately 40 to 55 percent of total cost at the LMM, declining proportionally at higher EV); legal fees including buyer counsel, seller counsel, lender counsel, and specialty counsel (20 to 30 percent); quality-of-earnings work plus transaction diligence (10 to 15 percent); R&W premium plus retention reserve (5 to 12 percent at 2.5 to 3.0 percent of limit pricing per the WTW Insurance Marketplace Realities Spring 2025 R&W update with 63% RWI adoption in the ABA 2025 study, see cross-link to the CT Acquisitions R&W Insurance Carrier Comparison report); and tax, HSR, escrow, and other costs (5 to 10 percent). The 2026 HSR fee schedule operates on six tiers from $35,000 to $2,460,000 per the FTC 2026 HSR Thresholds and Filing Fees notice (cross-link to the CT Acquisitions HSR Threshold Avoidance Database). Houlihan Lokey reported fiscal-year 2025 revenue of $2.39 billion in its M&A practice per the Houlihan Lokey FY2025 Form 10-K, with Corporate Finance up 38% year over year and representing 64% of firm revenue.

Third, the cost-reduction levers that matter most in 2024-2026 are: (a) the no-seller-indemnity / RWI-only structure that eliminates indemnity escrow and reduces indemnity legal complexity per Gallagher 2026; (b) the Lehman-formula tiered advisor fee scaled by deal size (5/4/3/2/1 or Modified Lehman 10/8/6/4/2), which caps high-EV advisor cost while preserving incentive at the LMM; (c) in-house counsel substitution at PE serial acquirers; (d) AI-assisted due-diligence tooling that has compressed QofE and contract-review hours by 20 to 40 percent through 2024-2026; and (e) multi-deal master service agreements with Big 4 deal advisors that capture 10 to 25 percent volume discounts off list rates.

Last updated: June 22, 2026.

2. Methodology + Scope

This report measures all-in closing costs for US private-target M&A transactions in the $5 million to $500 million enterprise value (EV) range that signed or closed between January 1, 2024 and June 15, 2026. The cost universe covers twelve discrete categories detailed in Section 3 below. Each cost line is benchmarked against one or more of the following primary sources:

• The ABA 2025 Private Target Mergers & Acquisitions Deal Points Study (139 transactions, mostly below $200M EV, signed in 2024 through Q1 2025) and the corresponding K&L Gates, Bass Berry & Sims, and Mondaq recaps.
• The SRS Acquiom 2025 Deal Terms Study covering more than 2,200 transactions worth $505 billion closed 2019-2024, plus the SRS Acquiom 2026 update.
• The BTI Consulting Group Premium Rate research and the BTI Practice Outlook 2026.
• The FTC 2026 HSR Thresholds and Filing Fees notice.
• The WTW Insurance Marketplace Realities Spring 2025 R&W report, Gallagher 2026, and the Horton Group Q4 2025 RWI Market Update.
• The Houlihan Lokey FY2025 Form 10-K and selected SEC filings disclosing transaction expense definitions.
• The Pitchbook 2025 Annual US PE Middle Market Report and the Pitchbook 2025 Annual US PE Breakdown.
• Practitioner cost surveys from M&A Community, Eton Venture Services, First Page Sage, RoseBiz, Firmex / Axial, DueDilio, Mainshares, Rejigg, and Capstone Partners (cited inline where applicable).

Each cost line is tagged with a confidence rating of HIGH, MEDIUM, LOW, or GAP. HIGH means at least two corroborating primary sources. MEDIUM means triangulated practitioner data. LOW means a single source with material uncertainty. GAP means the data is not publicly available at line-item granularity and only practitioner ranges are reported.

The report excludes: stock-for-stock public-to-public mergers (which carry different cost economics), regulated transactions in banking and insurance with FDIC or state insurance commissioner approval processes (cost-additive in non-comparable ways), and bankruptcy 363 sales (where buyer covers debtor counsel and creditor-committee counsel costs that distort the comparison).

3. Closing Cost Macro Framework: Buyer vs Seller, Funds Flow, and the 1% Rule Debunked

3.1 The total cost stack

Twelve categories make up the bulk of every middle-market closing cost stack. Buyer-paid items are marked (B), seller-paid (S), and frequently split items (B/S):

1. Legal fees, buyer counsel (B) and seller counsel (S)
2. Quality of Earnings and financial due diligence (B, occasionally a sell-side QofE paid by seller)
3. Tax due diligence and structuring (B and S separately)
4. M&A advisor / investment bank success fee (S, sometimes B on buy-side mandate)
5. R&W insurance premium and underwriting fee (B/S, increasingly cost-shared or buyer-only)
6. Regulatory and antitrust counsel plus HSR filing fee (B)
7. Other due diligence: environmental, IT, cyber, HR, insurance broker pre-close (B)
8. Debt financing: arrangement fees, OID, lender’s counsel (B)
9. Escrow agent, paying agent, stockholder representative (B/S split per the merger agreement)
10. Rollover and management equity structuring (B/S)
11. Working capital true-up and post-close administration (B/S)
12. Transition services agreement (TSA) (B pays S on a cost-plus or fixed-fee basis)

3.2 Buyer vs seller split

Across the SRS Acquiom 2025 Deal Terms Study dataset of more than 2,200 transactions worth $505 billion that closed between 2019 and 2024, transaction expenses are most commonly netted out at closing via the funds flow. The seller pays its own counsel, its M&A advisor success fee, and the broker for any tail insurance. The buyer pays its counsel, its QofE provider, tax due diligence, financing arrangement, and most regulatory filings.

In R&W specifically, Gallagher 2026 notes that the pricing difference between zero-seller-indemnity and partial-seller-indemnity structures is now largely immaterial, and many sellers in competitive processes expect a true walkaway with de minimis or zero indemnity. The R&W premium plus retention is increasingly buyer-only in deals brokered to financial buyers.

3.3 Closing-day funds flow on a typical LMM deal

A typical LMM funds flow on a $25M EV transaction routes:

• Gross purchase price wired by buyer (or paying agent on buyer’s behalf) to the paying agent escrow.
• Seller’s M&A advisor success fee paid out of seller proceeds at closing.
• Seller’s counsel fees paid out of seller proceeds.
• Indemnity escrow (where retained) withheld: typically 0.5% to 1.0% of EV per SRS Acquiom 2025.
• PPA / working-capital true-up escrow withheld: median approximately 1% of transaction value per SRS Acquiom 2025.
• Stockholder rep expense fund withheld: typically $100,000 to $500,000.
• Buyer expenses paid separately by buyer.

3.4 The 1% rule debunked

A common founder forum claim is that selling a business costs about 1% in fees. This figure is roughly accurate only for upper-middle-market transactions above $250 million EV, where advisor fees compress to 1.0 to 1.5 percent and other costs scale down. At sub-$10 million EV the all-in figure is roughly 10x that. The corrected ranges in this report draw from the M&A Community 2025 fee survey, the Eton Venture Services 2026 fee guide, the First Page Sage 2025 advisory benchmark, and the RoseBiz 2024-2025 fee survey.

Confidence: HIGH on framework. MEDIUM on precise basis-point distributions because deal-by-deal expense disclosures are sparse outside of SPAC and public-buyer transactions.

4. Legal Fees by Tier: Wachtell, Kirkland, Goodwin, Foley, and Regional

4.1 BTI Consulting Premium Rate context

The BTI Consulting Group Premium Rate research identifies the highest hourly billing rates at top-tier US firms in the range of $2,100 to $2,620 per hour for the most senior corporate partners as of 2025. The BTI Practice Outlook 2026 confirms M&A as a practice area where clients accept these premium rates rather than push back. The BTI Client Service A-Team 2025 notes A-Team firms charge premium rates and clients absorb 6 to 9 percent annual rate increases at the top tier.

BTI does not publish the full survey publicly. The Mad Clientist blog releases data points throughout the year, and the underlying client interview dataset is sold to law-firm subscribers. The ranges below are triangulated from BTI’s public commentary plus filed fee applications in bankruptcy court, which are the most reliable public record for actual billed rates.

4.2 Tier 1: Top-tier (Wachtell, Skadden, Sullivan & Cromwell, Davis Polk, Cleary, Cravath)

Partner billing rates as of 2025-2026:

• Senior corporate partners: $2,100 to $2,800 per hour
• Mid-level partners: $1,700 to $2,200 per hour
• Senior associates: $1,400 to $1,800 per hour
• Mid-level associates: $1,100 to $1,500 per hour
• Junior associates: $850 to $1,150 per hour
• Paralegals: $475 to $725 per hour

These firms are typically engaged only on transactions of $500 million or more EV or where novel structural and regulatory complexity demands a top-of-market team. Source: BTI Consulting plus filed fee applications.

4.3 Tier 2: Large-PE shops (Kirkland & Ellis, Latham & Watkins, Paul Weiss, Sidley, Weil Gotshal, Gibson Dunn, Simpson Thacher, Ropes & Gray)

• Senior corporate partners: $1,800 to $2,400 per hour
• Mid-level partners: $1,500 to $2,000 per hour
• Senior associates: $1,250 to $1,650 per hour
• Mid-level associates: $1,000 to $1,400 per hour
• Junior associates: $750 to $1,050 per hour

These are the workhorse firms for the upper middle market ($250M to $500M EV) and the standard buyer counsel choice for KKR, Blackstone, Apollo, Carlyle, TPG, Bain Capital, Advent International, and the rest of the large-PE bench.

4.4 Tier 3: Mid-PE and growth (Goodwin, Cooley, Wilson Sonsini, Fenwick & West, Orrick, DLA Piper, Morgan Lewis)

• Senior corporate partners: $1,500 to $2,000 per hour
• Mid-level partners: $1,200 to $1,650 per hour
• Senior associates: $950 to $1,300 per hour
• Mid-level associates: $750 to $1,050 per hour

These firms dominate growth-equity and venture-tech M&A and increasingly compete with Kirkland on PE platform deals in the $100M to $300M EV range.

4.5 Tier 4: LMM workhorses (Foley & Lardner, Faegre Drinker, Baker & Hostetler, Polsinelli, Reed Smith, Bass Berry & Sims, Holland & Knight)

• Senior corporate partners: $1,100 to $1,500 per hour
• Mid-level partners: $850 to $1,200 per hour
• Senior associates: $700 to $950 per hour
• Mid-level associates: $550 to $750 per hour

These are the practical choice for LMM buyers on $25M to $150M EV deals where rate efficiency matters.

4.6 Tier 5: Regional and local firms

• Partners: $475 to $850 per hour
• Associates: $325 to $550 per hour
• Paralegals: $175 to $275 per hour

Used routinely on sub-$25 million EV LMM transactions, particularly where buyer or seller is family-owned or first-time.

4.7 Partner rate evolution 2024-2026

The BTI Practice Outlook 2026 reports continued rate inflation at a pace meaningfully above CPI, driven by M&A demand recovery, AI-tool premium pricing, and rising associate base salaries. The BTI Client Service A-Team 2025 notes clients absorb 6 to 9 percent annual rate increases at the top tier.

4.8 Total legal fees by deal-size band (buyer plus seller counsel combined)

Ranges reflect the gap between Tier 5 and Tier 1 firms doing the same scope. A $100 million EV deal staffed Tier-1-on-both-sides could run $1.5 million or more on each side; the same deal staffed Tier-4-on-both-sides could close at $400,000 total.

Confidence: HIGH on tier rates (filed fee applications corroborate). MEDIUM on totals (scope creep, regulatory complexity, and dispute frequency drive significant variance within band).

5. Tax Advisor Fees: Big 4, Section 338(h)(10), Section 1060, Andersen, Marcum, RSM

5.1 Big 4 tax due diligence

Deloitte, PwC, EY, and KPMG charge engagement fees of approximately $200,000 to $800,000 for full Transaction Services scope (financial plus tax) on middle-market deals, with tax DD as a discrete deliverable typically running 25 to 40 percent of that total per Mergers & Inquisitions on Big 4 Transaction Services. The Big 4 deal advisory teams compete on platform deals against Alvarez & Marsal, FTI Consulting, AlixPartners, Riveron, Houlihan Lokey Financial Due Diligence, and the elite specialist independents.

For the LMM (deals in the $30M to $80M range typical of PE platform add-ons), tax DD alone typically runs $15,000 to $35,000, scaling to $50,000 to $150,000 on $100M to $300M deals and $150,000 to $400,000 on $300M to $1B deals per Peony Due Diligence Costs 2026.

5.2 Section 338(h)(10) election cost

The Section 338(h)(10) election allows a stock purchase to be treated as an asset purchase for tax purposes, generating a step-up in basis for the buyer at the cost of higher seller tax. Modeling the election typically costs:

• $5,000 to $15,000 in tax advisor modeling
• $5,000 to $20,000 in additional purchase agreement drafting
• Allocation work under Section 1060 typically $10,000 to $40,000

5.3 Section 1060 allocation advisory

Section 1060 of the Internal Revenue Code requires the buyer and seller to agree on allocation of the purchase price among classes of assets: Class I cash, Class II actively traded financial assets, Class III accounts receivable, Class IV inventory, Class V real and tangible personal property, Class VI intangibles, and Class VII goodwill and going concern. Big 4 allocation studies run $25,000 to $75,000. Boutique tax-and-valuation shops including Marcum, Andersen, and EisnerAmper run $15,000 to $40,000.

5.4 Tax structure modeling

For deals with rolled-over equity, founder QSBS positions, or cross-border legs, dedicated tax structure modeling runs $25,000 to $150,000 on top of base DD. Andersen Tax, RSM US, BDO USA, and Crowe LLP are the most-cited boutiques outside Big 4 per Peony Tax DD Checklist 2025.

5.5 QSBS cross-link

QSBS (Section 1202) qualification analysis is frequently bundled into the tax DD scope when sellers are individual founders. State conformity to the federal QSBS exclusion varies materially (see the CT Acquisitions QSBS State Conformity report under Wave 14). California’s historical non-conformity drove an estimated $250,000 to $1,000,000 in incremental state tax structuring on each California-based QSBS-eligible transaction. The partial conformity changes effective 2025 ease but do not eliminate this work.

Confidence: HIGH on Big 4 fee bands. MEDIUM on boutique ranges (varies by relationship and complexity).

6. Quality of Earnings (QofE) Provider Rankings and Fees

6.1 Top-tier QofE providers (Big 4 plus elite specialists)

• EY-Parthenon Transaction Diligence
• KPMG Transaction Services
• Deloitte M&A Transaction Services
• PwC Deals
• Alvarez & Marsal Transaction Advisory
• AlixPartners
• FTI Consulting M&A Advisory
• Houlihan Lokey Financial Due Diligence
• Riveron

6.2 Mid-tier (national accounting firms)

• BDO USA Transaction Advisory
• Grant Thornton Transaction Services
• RSM US Transaction Advisory
• CohnReznick Value Consulting
• Cherry Bekaert Transaction Advisory
• Marcum Transaction Advisory
• Wipfli Transaction Advisory
• Plante Moran Transaction Advisory
• Eide Bailly Transaction Advisory
• Crowe LLP Transaction Services
• Citrin Cooperman Transaction Advisory
• Withum Smith+Brown Transaction Services
• EisnerAmper Transaction Advisory
• Friedman LLP Transaction Advisory

6.3 LMM specialists

• Capstone Partners
• Embarc Advisors
• LCG Advisors
• DueDilio platform (broker)
• Calvetti Ferguson

6.4 QofE fee bands by deal size

Based on practitioner data and published price guides:

Sources: DueDilio QofE Guide 2025, Mainshares, Eton QofE Cost 2026, Rejigg.

6.5 QofE scope

A standard QofE engagement covers: LTM earnings normalization; quality-of-earnings adjustments (non-recurring, owner-related, related-party); working capital analysis and target-WC computation support; adjusted EBITDA build with full bridge to GAAP net income; revenue and gross-margin quality testing; customer concentration and cohort analysis; key performance indicator operational diligence; cash proof and reconciliation; debt and debt-like items schedule; and sell-side databook preparation (sell-side QofE only).

6.6 2024-2026 QofE pricing dynamics

Pitchbook PE Breakdown data and ACG Middle Market Growth commentary reflect that PE deal volume fell roughly 20 percent in 2023 and rebounded partially in 2024-2025. The pricing impact on QofE providers split as follows: Big 4 list rates rose 5 to 8 percent annually with partner billable rates, but mid-tier firms faced competitive pressure as PE buyers shopped multiple proposals on each platform. Capstone Partners and similar middle-market shops explicitly position their fee structure as favorable relative to the large accounting firms for the same scope of work per Capstone Partners: Getting the Most from QofE.

A material 2024-2026 trend is buy-side QofE compression on PE add-ons where the same Big 4 firm has already done a sell-side QofE on the target, leading to scope reduction and discounts of 25 to 40 percent on the buy-side mandate.

Confidence: HIGH on fee bands (multiple corroborating practitioner sources). MEDIUM on Big 4 vs mid-tier discount differential (private negotiation).

7. R&W Insurance Premium and Retention

Detailed carrier-by-carrier coverage is treated in the CT Acquisitions R&W Insurance Carrier Comparison report (Wave 14). Summary benchmarks as of mid-2026 follow.

7.1 Premium pricing

The R&W insurance market entered a soft / cooling phase from late 2023 through 2024, with premiums dipping from approximately 5% of limit in early 2022 to a low band of 2.0 to 2.5 percent of limit in late 2024 per the WTW Insurance Marketplace Realities Spring 2025 R&W report. Through 2025 and into Q1-Q2 2026 premiums firmed back up, with the most commonly cited band now 2.5 to 3.0 percent of limit for clean transactions and 3.0 to 4.0 percent for harder-to-place sectors such as healthcare, financial services, and distressed assets per the Horton Group RWI Q4 2025 Market Update.

Mega-deal premiums (limits above $100 million) saw the sharpest rate increases per Marsh 2025 data, reflecting both demand and an increase in claims activity per Insurance Business Mag on Marsh.

7.2 Retention (deductible)

Initial retention has compressed from a 2018 average of approximately 2.77 percent of EV down to approximately 0.5 percent of EV in 2025-2026, typically dropping to around 0.4 percent after 12 months of coverage per Gallagher 2026. For deals above $250 million EV the retention can drop to 0.3 percent of EV. Below $50 million EV the floor is often 0.75 to 1.0 percent.

7.3 Underwriter due diligence allowance

Underwriters require their own counsel to review buyer DD materials. The underwriting fee (paid by the insured) typically runs:

• $30,000 to $50,000 on sub-$50M EV deals
• $50,000 to $100,000 on $50M to $200M EV deals
• $75,000 to $150,000+ on $200M to $1B deals

7.4 RWI adoption rate

The ABA 2025 Private Target M&A Deal Points Study found 63 percent of analyzed deals referenced RWI vs 55 percent in the 2023 study, with K&L Gates confirming RWI is now the default in middle-market PE-led transactions. Cooley M&A notes the cooling market in 2024 made RWI viable on smaller deals than previously, with carriers willing to write limits below $5 million on sub-$25 million EV transactions (cross-link to the CT Acquisitions R&W Carrier Comparison report).

7.5 Total R&W stack example

On a $100 million EV transaction with $10 million of R&W limit (a typical 10 percent of EV):

• Premium at 2.75 percent of limit = $275,000
• Underwriting fee = $50,000 to $75,000
• Retention (buyer self-insures up to 0.5 percent of EV) = $500,000 capital reserved, not paid
• Broker fee (typically commission embedded in premium) = no separate line item
• All-in upfront cash cost = $325,000 to $350,000 plus the self-insured retention reserve

Confidence: HIGH on premium and retention ranges. MEDIUM on underwriting fee (varies by carrier).

8. Investment Bank and M&A Advisor Fees: Lehman Formula, Modified Lehman, 9-Band Table

8.1 Sell-side advisor tiers

Tier 1: middle-market bulge and elite (deals $100M to $2B EV)

• Houlihan Lokey: total revenue fiscal year 2025 of $2.39 billion (year ended March 31, 2025), with Corporate Finance (M&A advisory) up 38 percent year over year and representing 64 percent of firm revenue per the Houlihan Lokey 10-K FY2025. Houlihan ranked #1 US M&A advisor by deal count for ten consecutive years through 2025 per the Houlihan Lokey FY2025 Earnings Release.
• Lincoln International: focused on transactions $250M to $2B EV; net income $214.1 million in 2025 vs $163.3 million in 2024 driven by sell-side M&A advisory rebound.
• William Blair, Lazard Middle Market, Robert W. Baird, Stifel, Piper Sandler, Raymond James.

Sell-side success fee bands typically 1.0 to 2.0 percent on $250M to $1B deals, declining to 0.75 to 1.5 percent above $1B.

Tier 2: middle / LMM (deals $25M to $300M EV)

• DC Advisory, Capstone Partners, BDO Capital, Configure Partners, DA Davidson, Founders Advisors, Avondale Partners, Greenhill MM, Moelis MM, Solomon Partners, Bay Street Advisors.

Sell-side success fee bands 1.5 to 3.5 percent on $50M to $250M deals.

Tier 3: LMM and boutique (deals $5M to $75M EV)

• Local and regional advisory shops, industry-vertical specialists, business broker hybrids.

Sell-side success fees 3 to 6 percent with minimums of $250,000 to $1,000,000.

8.2 Lehman formula and Modified Lehman

The original Lehman formula (5/4/3/2/1 across $1 million tranches up to $5 million and 1 percent thereafter) is essentially obsolete for any deal above $5 million. The Modified Lehman variants now dominate. The most common middle-market modified scale is the Double Lehman (10/8/6/4/2) and the further-modified 3-3-2-1-1 scale per Auxo Capital Advisors.

The Wikipedia reference summary notes the Lehman Formula as the historic basis and confirms current practice is tiered Modified Lehman or blended-percentage with minimum floors per Wikipedia: Lehman Formula.

Sample Modified Lehman (Double Lehman):

• 10 percent of first $1 million
• 8 percent of second $1 million
• 6 percent of third $1 million
• 4 percent of fourth $1 million
• 2 percent of everything thereafter

On a $25 million deal this produces a $748,000 success fee, blended at approximately 3.0 percent.

8.3 Tiered / hurdle structure

A common 2024-2026 structure ties success fee to outcome thresholds:

• 1.5 percent base on price up to $X
• 2.5 percent on price between $X and $Y
• 4.0 to 6.0 percent on price above $Y

This aligns advisor incentive to maximize price.

8.4 Minimum fees

Practitioner data clusters minimum fees as follows per the M&A Community Fee Survey 2025, Eton 2026 Fee Guide, and RoseBiz 2024-2025:

• LMM boutique: $150,000 to $500,000
• Middle-market: $750,000 to $1,500,000
• Upper middle-market: $1,000,000 to $3,000,000
• Bulge bracket: $3,000,000 and above

8.5 Median sell-side advisor fee percent by deal size (2025)

Sources: First Page Sage 2025, Firmex / Axial M&A Fee Guide US, M&A Community 2025.

8.6 Buy-side advisor fees

Buy-side mandates typically run 0.5 to 1.5 percent of EV with monthly retainers per Dealroom Buy-Side M&A Fees. PE platforms with in-house M&A teams often skip the buy-side advisor entirely on platform add-ons; standalone family-office and corporate buyers routinely engage buy-side advisors.

8.7 Capital markets advisor

For debt-funded LBOs, a separate capital-markets advisor or arranger is engaged (frequently the same middle-market bank handling the M&A advisory mandate). Capital-markets fees of 0.5 to 1.0 percent of debt facility (in addition to lender arrangement fees, see Section 11).

Confidence: HIGH on fee bands (corroborated across at least four practitioner sources). MEDIUM on minimum fees (vary materially by advisor relationship).

9. Due Diligence Other Costs: Environmental, HR, IT/Cyber, Operational, Insurance

9.1 Environmental due diligence

A Phase I Environmental Site Assessment under ASTM E1527-21 (the current EPA-recognized standard since February 2024) typically costs $2,200 to $5,000 per site for standard commercial properties, rising to $5,000 to $10,000+ for complex industrial sites or properties with long operational history per A3E Phase I ESA Cost 2026 and Aegis Environmental 2025.

A Phase II ESA (when Phase I identifies recognized environmental conditions) typically costs $10,000 to $50,000+ depending on testing scope, sample count, and required remediation modeling.

Total environmental DD on a multi-site acquisition (for example a 25-location services platform) runs $50,000 to $250,000.

9.2 HR / benefits due diligence

HR DD scope includes employee benefits plan analysis, ERISA compliance review, multi-employer pension withdrawal liability exposure, equity-compensation review, and employment-agreement and restrictive covenant analysis (cross-link to CT Acquisitions Non-Compete report under Wave 14):

• LMM: $15,000 to $40,000
• MM: $40,000 to $100,000
• Upper MM: $75,000 to $200,000

9.3 IT / cybersecurity due diligence

IT DD scope: infrastructure inventory, application-stack mapping, security-controls assessment, data-privacy posture (GDPR, CCPA, state privacy laws), incident-response history. Cybersecurity-specific DD includes pen test, dark-web exposure check, MFA / EDR / SOC posture review:

• LMM: $15,000 to $50,000
• MM: $50,000 to $150,000
• Upper MM: $100,000 to $400,000

9.4 Operational / commercial due diligence

Commercial DD (market sizing, customer interviews, win/loss analysis, competitive landscape) is most common on PE platform investments. Boutiques such as L.E.K. Consulting, Bain Consulting CDD, McKinsey CDD, Alvarez & Marsal CDD, and OC&C dominate:

• LMM: $25,000 to $100,000
• MM: $100,000 to $350,000
• Upper MM: $350,000 to $1,000,000+

9.5 Insurance broker pre-close

Pre-close insurance review (P&C, D&O, EPLI, cyber) and broker placement: $10,000 to $50,000 typical engagement fee; broker is then on commission post-close.

Confidence: HIGH on environmental (published rate cards). MEDIUM on HR, IT, CDD (varies by complexity).

10. HSR 2026 Fee Schedule and Antitrust Counsel

10.1 Antitrust framework context

The Hart-Scott-Rodino Act of 1976 requires pre-merger notification to the FTC and DOJ Antitrust Division for transactions meeting size-of-transaction and size-of-person thresholds. The 30-day initial waiting period (15 days for cash tender offers and bankruptcy 363 sales) runs from filing acceptance unless either agency issues a Second Request, which extends the waiting period by an additional 30 days from substantial compliance. The thresholds and filing fees are adjusted annually by the FTC based on changes in the gross national product. The applicable filing fee is fixed at the time of filing. Cross-link to the CT Acquisitions HSR Threshold Avoidance Database (Wave 12) for structuring strategies around the threshold.

10.2 HSR filing fees (2026 schedule)

The FTC 2026 HSR fee schedule, effective February 17, 2026, sets six fee tiers per the FTC notice, the Sidley Austin recap, and the White & Case alert:

The size-of-transaction threshold for reporting in 2026 is $133.9 million (up from $126.4 million in 2025). One party must have global sales or assets of at least $267.8 million and the other party at least $26.8 million per Akin Gump. For 2025 the size-of-transaction threshold was $126.4 million and the fee schedule (effective February 21, 2025) was substantially similar with slightly lower fee amounts in each tier per the FTC 2025 HSR Thresholds notice.

10.3 HSR antitrust counsel

Counsel fees for HSR filing preparation and review:

• Simple no-overlap filing: $25,000 to $60,000
• Standard filing with substantive analysis: $60,000 to $150,000
• Filing with substantive overlap or second-request risk: $150,000 to $500,000+
• Second request response: $500,000 to $5,000,000+

10.4 State AG notification

State Attorney General notification requirements have proliferated, particularly in healthcare (see the CT Acquisitions State AG Healthcare PE Enforcement Tracker under Wave 10). Notable jurisdictions requiring 60 to 180 day pre-close notice for healthcare transactions include California, New York, Oregon, Washington, Massachusetts, Illinois, Indiana, Minnesota, Nevada, New Mexico, Rhode Island, Vermont, and Connecticut, among others. Counsel costs for healthcare AG filings: $25,000 to $150,000 per state.

10.5 CFIUS counsel

For cross-border transactions with foreign buyers, voluntary CFIUS notice or mandatory declaration counsel fees:

• Declaration only: $50,000 to $150,000
• Notice with full mitigation negotiation: $250,000 to $1,000,000+

10.6 Industry-specific regulatory

• Banking (Bank Holding Company Act filings, OCC, FDIC, state banking): $100,000 to $500,000 counsel
• Telecom (FCC license transfer): $50,000 to $300,000
• Healthcare licensure (Medicare 855A CHOW, state license transfers): $50,000 to $250,000
• Defense contractor (DCAA / DCMA novation, ITAR): $100,000 to $400,000

Confidence: HIGH on HSR (FTC published). MEDIUM on regulatory counsel ranges.

11. Debt Financing Costs: Commitment Fees, OID, Arrangement, Lender Counsel

11.1 Commitment fees

Commitment fees on committed debt financing typically run 0.5 to 1.0 percent of facility, paid upfront upon signing the commitment letter.

11.2 Original Issue Discount (OID)

OID for unitranche and direct-lender deals in 2024-2026 typically runs 1.0 to 2.5 percent of principal, paid as a discount at funding (lender funds $98.5 million for a $100 million face loan at 1.5 percent OID).

11.3 Arrangement / underwriting fees

• Arrangement fees on senior debt: 2.0 to 3.0 percent of facility for committed underwritten deals; 1.5 to 2.5 percent for clubbed direct-lending facilities.
• Unitranche pricing in 2024 H1 clustered at SOFR plus 550-725 basis points for core and upper MM with 50-100 basis point step-downs at defined debt-ratio milestones per ABF Journal 2025 middle-market debt capacity research.
• All-in private credit yields for new deals ran 12 to 13 percent in H1 2024; all-in cash interest on quality MM credits clustered at 9 to 11 percent.

11.4 Agent / collateral monitoring fees

• Administrative agent fee: $25,000 to $100,000 per year
• Collateral monitoring: $25,000 to $75,000 per year
• Borrowing base agent (for ABL facilities): $35,000 to $100,000 per year

11.5 Lender’s counsel (buyer-paid)

Standard market practice is buyer pays lender’s counsel:

• Sub-$25M facility: $50,000 to $125,000
• $25M to $100M facility: $125,000 to $300,000
• $100M to $500M facility: $300,000 to $800,000
• $500M+ facility: $800,000 to $2,000,000+

11.6 Total debt fees as percent of facility

For a typical $50 million unitranche facility on a $100 million EV deal:

• OID 1.5 percent = $750,000 (deducted from funding)
• Arrangement fee 2.5 percent = $1.25 million
• Lender’s counsel = $175,000
• Commitment fee (refunded if drawn at close) = effectively $0 at close
• Admin agent year 1 = $50,000
• Total upfront debt cost = approximately $2.2 million, or 4.4 percent of facility / 2.2 percent of EV

Confidence: HIGH on unitranche pricing (Raymond James 4Q 2025 Debt Market Insight, Private Capital Global benchmarks, Wall Street Prep Unitranche Debt). MEDIUM on per-deal fee mix (varies by sponsor relationship).

12. Escrow, Paying Agent, and Stockholder Representative Fees

12.1 Escrow agent

Standard escrow agent fee structure:

• Setup fee: $3,000 to $10,000
• Annual administration: $4,000 to $15,000 per year
• Wire-transfer / disbursement fees: $25 to $75 per wire

Total escrow agent fees on a typical 18-month indemnity escrow: $8,000 to $25,000.

12.2 Paying agent

Paying agent fee structure (SRS Acquiom, Computershare, Continental Stock Transfer, American Stock Transfer):

• Base setup fee: $3,000 to $8,000
• Per-stockholder processing: $25 to $75
• Letter-of-transmittal handling: $5,000 to $15,000
• 1099 / K-1 issuance: $25 to $50 per holder

Total paying agent fees: $5,000 to $15,000 on a deal with up to 50 stockholders; $15,000 to $50,000 with broader cap tables.

12.3 Stockholder representative fees

SRS Acquiom’s stockholder representative engagement structure per SRS Acquiom: Shareholder Representation and SRS Acquiom: M&A Expense Fund:

• Base engagement fee: $10,000 to $35,000
• M&A expense fund (held separately from escrow for post-close third-party expenses): $100,000 to $500,000 typical
• Hourly post-close work billed against the expense fund

12.4 Who pays paying agent fees

SRS Acquiom’s review of more than 2,900 engagements over five years finds the dominant practice is seller-paid (deducted from proceeds), with an even split now used in approximately 10 percent of engagements. The paying agent agreement (PAA) typically allows the paying agent to collect the full amount from one party if the other does not pay.

12.5 Letter of transmittal processing

The paying agent processes letters of transmittal (LOTs) and W-9 / W-8 forms from each holder before disbursing proceeds. Holders who do not return LOTs within the cure window have their proceeds reverted to the surviving entity per the merger agreement.

Confidence: HIGH on escrow / paying agent base fees (SRS Acquiom published). MEDIUM on expense fund sizing (highly deal-specific).

13. Rollover and Management Equity Structuring Fees

13.1 Cross-link to CT Acquisitions internal benchmarks

CT Acquisitions maintains dedicated rollover-equity-benchmarks-2026 and founder-earnout-benchmarks-by-deal-size-2026 reports covering rollover quantum, structuring, and earnout terms. Summary:

• Rollover quantum in LMM and MM PE platform deals: 15 to 35 percent of seller proceeds typical.
• Earnout prevalence: down to 18 percent of deals in the ABA 2025 study from 26 percent in the 2023 study per the ABA 2025 Deal Points Study.

13.2 Personal tax advice for rolled-over founders

Founders with rolled-over equity require personal tax structuring distinct from corporate tax DD:

• Section 351 / 721 rollover structuring: $15,000 to $50,000
• QSBS preservation analysis (if applicable, cross-link to CT QSBS State Conformity report): $25,000 to $100,000
• Section 1042 ESOP rollover (if structured as ESOP exit): $50,000 to $250,000

13.3 Trust and estate planning

For founders crossing the threshold from operator to investor, estate planning becomes a material cost line (cross-link to the CT Acquisitions Family Office Succession report under Wave 11):

• Grantor retained annuity trusts (GRATs): $25,000 to $75,000 setup
• Spousal lifetime access trusts (SLATs): $40,000 to $125,000
• Family limited partnerships: $50,000 to $200,000

13.4 Management equity grant structuring

For rollover plus new management equity plan:

• 409A valuation: $7,000 to $25,000
• Management equity plan documentation: $20,000 to $75,000
• Profits interest vs option election analysis: $5,000 to $20,000
• Total: $35,000 to $120,000 typical

Confidence: HIGH on Section 351 / 721 fees. MEDIUM on estate planning (highly variable by founder net worth and complexity).

14. Post-Close Costs: Working Capital True-Up, Earnout Admin, Indemnification, TSA

14.1 Working capital true-up

Working capital true-up settlement under the merger agreement’s purchase-price-adjustment mechanic typically produces (cross-link to the CT Acquisitions Working Capital Peg report under Wave 14):

• Adjustment amount: median approximately 0.9 percent of transaction value when owed to buyers per the SRS Acquiom 2024 Working Capital PPA Study.
• Cost to compute and negotiate: $15,000 to $50,000 accountant fee plus $15,000 to $60,000 legal.
• Disputed WC true-ups go to an independent accountant (often a Big 4 or top mid-tier acting as arbitrator): $25,000 to $150,000.

14.2 Earnout administration

For deals with earnout structures (18 percent of ABA 2025 sample):

• Quarterly or annual KPI computation: $10,000 to $40,000 per year
• Disputes: independent accountant fees of $50,000 to $300,000

14.3 Indemnification claims processing

Stockholder rep handles indemnification claims out of the indemnity escrow:

• Counsel for stockholder rep on each claim: $25,000 to $200,000
• Drawdown from the M&A expense fund discussed in Section 12.3

14.4 Transition services agreement (TSA) cost

TSA pricing varies widely. Typical structures:

• Cost-plus 5 to 15 percent markup on services provided
• Fixed monthly fee with caps
• Per-FTE chargeback

TSA term typically 3 to 12 months. Total TSA cost as percent of EV: 0.25 to 2.5 percent depending on functional scope (IT, HR, finance, payroll, supply chain).

GAP: TSA cost is rarely disclosed at the line-item level in EDGAR filings. Practitioner ranges only.

15. By-Deal-Size Benchmark Tables: $5M to $500M EV

The following tables aggregate cost ranges from Sections 4 through 14 into all-in transaction-cost benchmarks. Each row assumes a typical PE platform buyer pattern: external counsel both sides, Big 4 QofE on buy-side, R&W placed, HSR if applicable, debt-financed at 50 percent LTV.

15.1 $5M EV (sub-LMM / search fund range)

15.2 $25M EV (LMM)

15.3 $50M EV (LMM / MM boundary)

15.4 $100M EV (MM)

15.5 $250M EV (upper MM)

15.6 $500M EV (upper MM / lower large-cap)

15.7 Cross-tier summary

The curve is asymptotic. Sub-$10 million deals run 10 percent or more on a combined basis driven by minimum-fee floors on advisor, QofE, R&W, and legal. Above $250 million, advisor compression brings the combined figure under 5 percent.

Confidence: HIGH on relative shape. MEDIUM on absolute precision (deal-by-deal variance of plus or minus 30 percent within band).

16. Cost-Reduction Strategies

16.1 No-seller-indemnity / RWI-only structure

Replacing a traditional seller-indemnity package (with 0.5 to 2.0 percent of EV held in indemnity escrow for 12 to 24 months) with a pure RWI structure eliminates:

• Seller-side reserve and escrow withhold
• Working capital tied up in held funds
• Stockholder rep claims-administration cost (partially)

The buyer absorbs the R&W premium (often shared) and self-insures the retention. In competitive sale processes the seller now expects this structure as default per Gallagher 2026 and CBIZ R&W in 2025 M&A. Cross-link to the CT Acquisitions R&W Carrier Comparison report.

16.2 Lehman-formula tiered advisor fee

Structuring the success fee as Modified Lehman (for example, 3-3-2-1-1) rather than flat 4 percent on a $25 million deal saves approximately $250,000 in advisor fee while preserving advisor upside on overperformance.

16.3 In-house counsel substitution

PE platforms with general counsel can use in-house lawyers for first-draft purchase agreement work, ancillary documents, and disclosure schedule review, reducing external counsel hours by 30 to 50 percent.

16.4 AI-assisted due diligence tools

2024-2026 saw rapid adoption of AI-assisted DD tooling for contract review (Kira Systems, eBrevia, Luminance, Robin AI, Harvey), data-room analytics (DealRoom AI, Datasite Prisma), and financial reconciliation. Practitioners report 20 to 40 percent reduction in associate hours on standard DD scope when AI tooling is integrated, though net fee reduction is more modest because firms reprice the AI-augmented work.

16.5 Multi-deal master service agreements

PE platforms with frequent deal flow negotiate MSA pricing with QofE, environmental, IT DD, and counsel providers, typically locking in 10 to 25 percent discounts off list rates in exchange for committed annual volume.

16.6 Sell-side QofE precommitment

A seller commissioning a sell-side QofE upfront ($35,000 to $200,000 depending on size) often saves 25 to 40 percent of buy-side QofE cost as buyers reduce scope to verification rather than build.

16.7 Tail-policy stacking

For sellers, R&W tail insurance plus D&O tail typically costs 250 percent of the annual premium for a 6-year tail. Bundling with the M&A R&W policy at placement reduces the marginal incremental cost vs purchasing tail separately post-close.

Confidence: HIGH on structural strategies. MEDIUM on AI-assisted DD savings (still in early adoption and rapid evolution).

17. 2024-2026 Trends: Rate Inflation, QofE Compression, R&W Cycle, AI Tooling, Big 4 / Boutique Consolidation

17.1 Legal rate inflation

The BTI Practice Outlook 2026 confirms M&A as a practice area where premium rate inflation continues at 6 to 9 percent annually at the top tier, materially above CPI. Mid-tier firms have raised at 4 to 6 percent annually.

17.2 QofE pricing compression

PE deal slowdown in 2023-2024 forced mid-tier QofE providers (Grant Thornton, RSM, BDO, CohnReznick) into competitive RFP discounting on PE platform mandates. Big 4 list rates held but realized rates declined 5 to 10 percent as PE buyers shopped multi-bidder QofE engagements. Recovery in 2025-2026 deal flow has partially restored pricing power.

17.3 R&W soft / firming cycle

Premiums dipped from approximately 5 percent of limit (early 2022) to a low of 2.0 to 2.5 percent (late 2024), then firmed back to 2.5 to 3.0 percent through 2026 as claims activity rose and capacity tightened per WTW Spring 2025 RWI, Marsh 2025, and the Horton Group Q4 2025 update.

17.4 AI-DD tooling disruption

The 2024-2026 period saw a shift from AI-augmented billing (lawyer hours preserved, AI used as productivity layer) toward AI-priced fixed-fee scope offerings. Several mid-tier firms launched AI-priced contract-review and disclosure-schedule offerings at 50 to 65 percent of traditional hourly billing.

17.5 Big 4 + boutique consolidation

The 2024-2026 period saw continued consolidation among transaction-advisory boutiques. Notable PE-backed deals in the accounting / advisory space include EisnerAmper (TowerBrook), Citrin Cooperman (New Mountain Capital), Cherry Bekaert (Parthenon Capital), Aprio (Charlesbank), and Withum (Cinven announced April 2026 close). The consolidation pressure has accelerated pricing power at the consolidated mid-tier vs Big 4.

17.6 ABA 2025 study highlights

The ABA 2025 Private Target Deal Points Study (139 deals, $25M to $900M, majority below $200M, signed 2024 through Q1 2025) found:

• 63 percent of deals referenced RWI (up from 55 percent in the 2023 study)
• 18 percent used earnouts (down from 26 percent)
• Median indemnity cap of 10 percent of purchase price for non-fundamental reps remains stable
• Median survival period for general reps of 18 months remains stable

Sources: K&L Gates 2025 Recap, Bass Berry & Sims 2025 Recap, Mondaq 2025 Recap.

17.7 Pitchbook 2025 deal-volume context

The Pitchbook 2025 Annual US PE Middle Market Report records US PE middle-market deal value climbing 8.5 percent year over year to $410.7 billion across an estimated 4,018 transactions (deal count up 16 percent year over year). Full-year US PE deal value reached $1.2 trillion, the second-highest total on record after 2021. Exits rose to an estimated 1,022 transactions totaling $140.4 billion (up double digits by count and surpassing pre-pandemic averages for the first time since 2021). Fundraising fell more than 40 percent year over year to $94.8 billion, the weakest year since before the pandemic per the Pitchbook 2025 Annual US PE Breakdown.

On multiples (cross-link to the CT Acquisitions Multiples report under Wave 14), Pitchbook 2024 data showed median EV/EBITDA buyout multiples of 15.5x for deals $1 billion and above, 12.8x for deals under $1 billion, and under 10x for deals below $100 million. GF Data records average TEV/EBITDA at 7.2x year-to-date 2025 for LMM transactions, with LMM entry multiples typically clustering in the 6x to 8x range vs 12x to 15x in large-cap PE per Pitchbook on Middle-Market PE Multiple Arbitrage, Capitalpad LMM PE Statistics 2026, and Forvis Mazars Q2 2025 MM M&A Insights.

The implication for closing costs: as deal multiples on LMM transactions remain near 7x EBITDA vs 15x for large-cap, the absolute EV at sub-$50 million EBITDA targets stays low enough that fixed-cost components (HSR floors, escrow base fees, R&W minimums, advisor floors) drive a much higher percentage-of-EV total cost than on large-cap deals.

17.8 SRS Acquiom 2025 / 2026 study highlights

The SRS Acquiom 2025 study (more than 2,200 deals, $505 billion aggregate, closed 2019-2024) and the 2026 update found:

• Special-purpose PPA escrows used in more than 75 percent of deals
• Median PPA escrow size approximately 1 percent of transaction value (stable)
• General indemnity escrow size has crept upward year over year
• Even-split paying-agent fees now approximately 10 percent of engagements (up from negligible historically)
• 2024 saw a 3x increase in jumbo transactions over $750 million vs 2023

Sources: Fasken 2026 Recap, DealLawyers 2025 Recap, ABF Journal 2025 Recap.

Confidence: HIGH on study summaries (multiple corroborating recap sources). MEDIUM on AI-tooling disruption magnitude (still in early measurement).

18. Named Closing Cost Disclosures from EDGAR (2024-2026)

Public buyer 10-K, 10-Q, and 8-K disclosures generally aggregate transaction costs rather than break out the specific advisor, legal, and tax components. Below are examples of disclosed transaction expense definitions and aggregate cost figures useful for benchmarking. Specific deal-level disclosures cited in the SEC filings vary in granularity.

18.1 Definitional template (from a typical 2025 8-K)

Transaction expenses commonly defined in merger agreements (per 2025 SEC filings) include all fees, costs, expenses, brokerage fees, commissions, finders’ fees, and disbursements of financial advisors, investment banks, data room administrators, attorneys, accountants, and other advisors and service providers; all bonuses, change-in-control payments, severance, retention, or similar payments; all filing fees payable to the Antitrust Authorities; and costs and expenses related to the preparation, filing, and distribution of proxy statements and SEC filings (composite definition, see FACT II Acquisition Corp 8-K 2025, Emmis Acquisition Corp 8-K 2025, Pelican Acquisition Corp 8-K 2025, Southport Acquisition Corp 8-K 2025, OTG Acquisition Corp 8-K 2025).

18.2 SPAC transaction-fee disclosures

SPAC business combinations typically disclose advisor fees as a percentage of trust funds:

• Emmis Acquisition Corp: advisor compensation 3.0 percent of cash held in trust at the business combination, with a $1.0 million minimum (per filed 8-K)
• Pelican Acquisition Corp: transaction fee 3.5 percent of IPO gross proceeds, with 1.0 percent subject to reduction based on capital retained in trust (per filed 8-K)
• Reimbursable expenses capped at $20,000 in standard SPAC structures
• Carlyle Secured Lending and Carlyle Secured Lending III filed 8-Ks in 2025 disclosing transaction expense templates for fund-level mergers (Carlyle SLC 8-K 2025 Ex 2.1, Carlyle SLC III 8-K 2025 Ex 2.1)

18.3 GAP on specific deal disclosures

Most private-target M&A transactions are completed by private buyers (PE) or by public buyers under materiality thresholds that do not require specific transaction-cost disclosure in the 10-Q or 8-K. The most useful public source for itemized transaction-cost disclosure is bankruptcy court fee applications (where the bidder won an auction in a Chapter 11 363 sale) and SPAC business combination proxies, where the SPAC must disclose all transaction-cost economics.

For a citation-grade benchmark of disclosed transaction costs, future research should focus on:

• Selected larger private-target acquisitions completed by public buyers in 2025-2026 where the 10-K MD&A breaks out transaction-related expenses
• Bankruptcy court 363 sale fee applications (Westlaw / PACER)
• IRS Form 8594 asset allocation schedules (where filed in SEC exhibits)

Confidence on cost definitions: HIGH. Confidence on disclosed deal-level expense percentages: MEDIUM-LOW given disclosure paucity (cross-link to the CT Acquisitions SEC Deal-Term report under Wave 14).

18.4 Practitioner reference points for benchmarking

In the absence of complete EDGAR cost-itemization, practitioners triangulate from the following public reference points to build deal cost models:

• Aggregate transaction-related expenses line item in the acquirer’s 10-Q immediately post-close, expressed as a percent of purchase price. Typical disclosures cluster at 1.5 to 4.5 percent of EV on $100 million to $500 million deals.
• Bankruptcy court fee applications in 363 sales filed in Delaware and Southern District of New York bankruptcy courts. These provide hourly rate, hours billed, and disbursements for buyer counsel, seller counsel (debtor counsel), and creditor-committee counsel.
• IPO prospectuses for newly listed acquirers that disclose pro-forma transaction cost detail on recent acquisitions.
• Form S-4 registration statements for public-to-public stock mergers, which disclose all financial-advisor, legal, accountant, and printer expenses in the Fees and Expenses of the Merger section.
• DEF 14A proxy statements that include go-shop / no-shop / break-fee disclosures and advisor opinions.
• 10-K MD&A disclosures of acquisition-related costs or business combination costs by segment.

The most useful 2024-2026 reference points for closing cost benchmarking by deal size are the Form S-4 fee tables filed in public-to-public mergers and the bankruptcy fee applications in major Chapter 11 sale processes. Building a clean benchmark from these public sources requires deal-by-deal triangulation, which the by-deal-size tables in Section 15 already incorporate via practitioner survey data.

19. Counter-Narrative Findings

Several widely repeated claims about M&A closing costs do not survive primary-source verification. The corrections below should be noted by founders and operators reading sell-side advisor pitch decks or generic blog content.

19.1 The 1 percent of EV claim

The claim that transaction costs run approximately 1 percent of enterprise value is roughly accurate only for transactions above $250 million EV and is approximately correct only for transactions above $1 billion EV. The figure understates true closing cost at the LMM by a factor of 10. As Section 15 demonstrates, at $5 million EV the all-in figure is 11 to 12 percent. At $25 million EV it is 8 percent. The 1 percent rule originated in large-cap public M&A commentary and was incorrectly extrapolated downmarket.

19.2 The buyer-pays-all-fees claim

The claim that the buyer absorbs the majority of transaction cost is correct in absolute dollars only at the upper middle market. At LMM (sub-$25 million EV), the seller-side advisor fee alone is typically 4 to 8 percent of EV. The seller’s percentage cost is higher than the buyer’s at sub-$50 million EV per the Section 15 tables.

19.3 The Lehman formula is current standard claim

The original 5/4/3/2/1 Lehman formula is essentially obsolete. The 2024-2026 standard is one of the Modified Lehman variants (Double Lehman 10/8/6/4/2 or 3-3-2-1-1) or a tiered hurdle structure per Auxo Capital. Founders who anchor advisor fee negotiation on the original Lehman formula either underprice or misunderstand the structure.

19.4 The R&W premium is a fixed industry rate claim

R&W premium has moved from approximately 5 percent of limit in early 2022 to a 2.0 to 2.5 percent low in late 2024 and back to 2.5 to 3.0 percent in 2026 per WTW and Horton Group. Pricing is cyclical, not static. The premium should be tested against the current market via at least three carrier quotes at placement.

19.5 The HSR threshold is constant claim

The HSR size-of-transaction threshold rises annually with GNP. The 2025 threshold was $126.4 million and the 2026 threshold is $133.9 million per the FTC. The applicable filing fee at the time of filing controls. Transactions that cleared the threshold in 2024 may not require filing in 2026 at the same EV.

19.6 The QofE-is-optional-at-LMM claim

Buy-side QofE is now standard practice on PE platform acquisitions and increasingly standard on independent sponsor deals above approximately $5 million EV. The 2024-2026 pricing has fallen low enough (sub-$25,000 at the small end per DueDilio) that the cost-benefit math favors a QofE on essentially any deal where buyer is institutional.

Confidence: HIGH on the corrected ranges (multiple corroborating sources, see Section 21).

20. Limitations and Data Gaps

This benchmark has several material limitations that future research can address.

• TSA cost disclosure is thin. TSA pricing varies widely and is rarely disclosed at the line-item level in 10-Q or 8-K filings. Practitioner ranges only.
• Private buyer disclosure is sparse. The majority of LMM and MM transactions are completed by PE platforms that do not file 10-Q or 8-K and therefore do not disclose itemized transaction cost. The most useful public source for itemized cost is bankruptcy court fee applications and Form S-4 fee tables in public-to-public mergers.
• Big 4 realized rates vs list rates. Big 4 publish list rates that are subject to MSA-level discount of 10 to 25 percent in PE platform engagements. Realized rate data is private.
• Geographic variance is undercaptured. The ranges in this report reflect US-wide averages weighted to coastal urban markets. Texas, Florida, Carolinas, and the upper Midwest tend to run 10 to 20 percent below the ranges; New York, San Francisco, and Boston tend to run 10 to 25 percent above.
• Sector variance is undercaptured. Healthcare, financial services, and regulated industries carry higher regulatory counsel costs that the generic ranges in this report do not capture in full. Manufacturing, distribution, and services typically run at or below the generic ranges.
• 2026 H2 data not yet available. The report cuts off at June 22, 2026. Q3 and Q4 2026 may show further movement in R&W pricing, advisor fee compression, and Big 4 discount discipline.

21. Related CT Acquisitions Research

This report cross-links to the following CT Acquisitions reports for deeper analysis on specific cost categories:

• Wave 14: SEC Deal-Term Report for itemized transaction-expense definitions, S-4 fee tables, and 10-K MD&A acquisition-cost disclosure benchmarks.
• Wave 14: R&W Insurance Carrier Comparison for carrier-by-carrier premium rates, claims experience, retention bands, and underwriting fee detail across AIG, Beazley, Chubb, Tokio Marine HCC, Liberty Mutual, Allied World, Concord, Euclid, QBE, and the rest of the active US R&W underwriter set.
• Wave 14: Working Capital Peg Report for SRS Acquiom working capital adjustment data, peg negotiation strategies, and dispute resolution mechanics.
• Wave 14: Multiples Report for Pitchbook, GF Data, S&P Capital IQ, and Capstone middle-market EV/EBITDA benchmarks by sector and deal size.
• Wave 14: QSBS State Conformity for state-level Section 1202 conformity tracking and structuring implications.
• Wave 14: Non-Compete Report for FTC final rule status, state non-compete law tracker, and HR-DD implications.
• Wave 14: SBA 7(a) Acquisition Financing Report for SBA-backed acquisition lending pricing, structure, and 2024-2026 program changes.
• Wave 12: HSR Threshold Avoidance Database for structuring strategies around the $133.9 million 2026 size-of-transaction threshold.
• Wave 12: Sponsor Concentration Report for analysis of fund-level concentration risk in the active US PE sponsor universe.
• Wave 13: Deal Pipeline Research for in-flight transaction tracker by sector and sponsor.
• Wave 11: Family Office Succession Report for founder-side estate planning, GRAT, SLAT, and family limited partnership benchmarks.
• Wave 10: State AG Healthcare PE Enforcement Tracker for state-by-state pre-close notice requirements in healthcare transactions.
• rollover-equity-benchmarks-2026 for rollover quantum, structuring, and post-close founder economic terms.
• founder-earnout-benchmarks-by-deal-size-2026 for earnout prevalence, KPI structures, and dispute resolution mechanics.

22. Sources (Primary)

22.1 Surveys and studies

• BTI Consulting Group Premium Rate research / The 32 Firms with the Highest Rates
• BTI Practice Outlook 2026
• BTI Client Service A-Team 2025
• BTI Most Recommended Law Firms 2025
• ABA Business Law Today: ABA 2025 Private Target M&A Deal Points Study
• K&L Gates: 2025 ABA Private Target M&A Deal Points Study
• Bass Berry & Sims: 2025 Private Target M&A Deal Points Study
• SRS Acquiom: 2025 M&A Deal Terms Study key trends
• SRS Acquiom: 2026 M&A Deal Terms Study
• SRS Acquiom: M&A Deal Terms 2026 Key Trends
• SRS Acquiom: 2025 Life Sciences M&A Study
• Fasken: SRS Acquiom 2024 M&A Deal Terms Study Recap
• Fasken: Private M&A Deal Trends to Watch (SRS Acquiom 2026 Study)
• ABF Journal: SRS Acquiom Releases 2025 M&A Deal Terms Study
• DealLawyers Blog: Study Private Target Deal Terms
• Mondaq: 2025 ABA Private Target M&A Deal Points Study
• Capstone Partners: Middle Market M&A Valuations Index

22.2 M&A advisor fees

• M&A Community: M&A Fees by Deal Size 2025
• First Page Sage: M&A Advisory Fee Structure 2025
• Eton Venture Services: M&A Advisory Fees 2026
• RoseBiz: M&A Advisor Fees 2024-2025
• Firmex / Axial M&A Fee Guide US
• Axial: Understanding Investment Banking Fee Structures
• Dealroom: Buy-Side M&A Fees Explained
• BizAdvisoryBoard: How Much Do M&A Advisors Charge
• Auxo Capital Advisors: Modified Lehman Formula
• Auxo Capital: M&A Advisor Fee Calculator
• Wikipedia: Lehman Formula
• Brentwood Growth: Lehman Formula Demystified
• Venture First: Success Fees and the Lehman Formula
• Exit Promise: Lehman Scale Formula
• Houlihan Lokey 10-K FY2025
• Houlihan Lokey 8-K FY2026 Q1
• Houlihan Lokey FY2025 Earnings Release

22.3 QofE

• DueDilio: QofE Analysis Guide 2025
• Mainshares: How Much Does a QofE Cost
• Embarc Advisors: Why Every M&A Deal Needs a QofE
• Calvetti Ferguson: Quality of Earnings Services
• PBS Brokers: Insights into QofE
• Eton Venture Services: QofE Report Cost
• LCG Advisors: Quality of Earnings Analysis
• Rejigg: Quality of Earnings Report
• Capstone Partners: Getting the Most from QofE Review
• SeaRidge Advisory: QofE Survival Guide for 2026 Exits
• Mergers & Inquisitions: Big 4 Transaction Services

22.4 Tax DD

• Deloitte: M&A Tax Talk
• Deloitte: M&A Tax Due Diligence and Structuring
• BPM: Tax Due Diligence Key Insights
• Peony: Tax Due Diligence Checklist 2025
• Peony: Due Diligence Costs 2026
• Boyum Barenscheer: M&A Due Diligence
• DataRooms.org: Due Diligence Costs
• Papermark: Due Diligence Cost 2026

22.5 R&W insurance

• Gallagher: Who Pays the RWI Premium and Retention in 2026
• WTW: Insurance Marketplace Realities 2025 Spring Update R&W
• Marsh / Insurance Business: R&W Premiums Rise as Mega Deals Hit Record Levels
• Insurance Business AU: Marsh R&W Premiums Rise
• Horton Group: RWI Q4 2025 Market Update
• Cooley M&A: R&W Insurance Cooling Market 2024
• Koley Jessen: R&W Insurance vs Traditional Indemnity
• Swiss Re: US P&C Outlook January 2026
• CBIZ: R&W in 2025 M&A Trends and Best Practices
• LegalClarity: What Is R&W Insurance

22.6 HSR and antitrust

• FTC: New HSR Thresholds and Filing Fees for 2026
• FTC: 2026 Update of Jurisdictional and Fee Thresholds Press Release
• FTC: New HSR Thresholds and Filing Fees for 2025
• White & Case: FTC Announces Annual Updates to US HSR Thresholds
• Akin: FTC Updates HSR Filing Fees and Revises Thresholds for 2026
• Covington & Burling: FTC Announces 2026 Update
• Steptoe & Johnson: FTC 2026 Adjustments to HSR Filing Thresholds
• Paul Hastings: FTC Announces Increased HSR Thresholds for 2026
• Reed Smith: FTC Announces Adjusted HSR Thresholds for 2026
• Sidley Austin: U.S. FTC Releases 2026 Thresholds for HSR Act Filings

22.7 Environmental

• ASTM E1527-21 Standard Practice for Phase I ESA
• A3E: Phase I ESA Cost 2026
• Aegis Environmental: Phase I ESA Costs 2025
• AEI Consultants: Phase I ESA
• CREtelligent: ASTM Standards for Phase I ESA
• Allen Matkins: Single ASTM Standard for Phase I ESA
• Haley & Aldrich: EPA Adopts ASTM E1527-21
• J.S. Held: ASTM 1527-21 Phase I ESA Standards Update
• Dudek: Phase I ESA Requirements

22.8 Debt financing

• ABF Journal: Stress-Testing Middle Market Debt Capacity 2025
• Raymond James 4Q 2025 Debt Market Insight
• Private Capital Global: Private Capital Debt Benchmarks
• Private Equity Bro: Unitranche Loans Pricing Structures
• Wall Street Prep: Unitranche Debt
• Case Western Law: Middle Market Unitranche
• NEPC: Quarterly Private Markets Report Q3 2025

22.9 Escrow / paying agent / stockholder rep

• SRS Acquiom: Paying Agent Agreements Who Pays the Fees
• SRS Acquiom: M&A Escrows and Payments
• SRS Acquiom: Shareholder Representation
• SRS Acquiom: M&A Escrow Services
• SRS Acquiom: M&A Paying Agent
• SRS Acquiom: M&A Expense Fund
• SRS Acquiom: Paying Agent Services Resources

22.10 EDGAR (2025 transaction expense definitions)

• FACT II Acquisition Corp 8-K FY2025 Ex 10.5
• Emmis Acquisition Corp 8-K FY2025 Ex 10.7
• Carlyle Secured Lending 8-K FY2025 Ex 2.1
• Pelican Acquisition Corp 8-K FY2025 Ex 1.2
• Southport Acquisition Corp 8-K FY2025 Ex 2.1
• Carlyle Secured Lending III 8-K FY2025 Ex 2.1
• OTG Acquisition Corp I 8-K FY2025 Ex 1.4

22.11 Pitchbook and market data

• Pitchbook 2025 Annual US PE Middle Market Report
• Pitchbook 2025 Annual US PE Breakdown
• Pitchbook: Middle-Market PE Multiple Arbitrage
• Capitalpad: LMM PE Statistics 2026
• Forvis Mazars: Q2 2025 MM M&A Insights

23. Frequently Asked Questions

Related research: for M&A multiples extracted from SEC EDGAR 8-K Item 2.01 + Rule 3-05 target financials disclosures (11,408 filings + 19.4% trigger rate); median public-buyer EV/EBITDA 9.8x; SaaS 6.1x EV/Rev + Rule of 40; healthcare 9.6x compression; data center 25-35x (Aligned/MGX $40B = largest data center deal ever); 42 mega-deal + 30 MM + 25 LMM serial-acquirer named extractions, see the 2024-2026 M&A Multiples Database (EDGAR + Rule 3-05).

Related research: for Working capital peg from SEC EDGAR 8-K + Big-4 deal advisory + 2 named Delaware Chancery rulings (SM Buyer v RMP Save Mart Feb 2024 + Northern Data AG v Riot Platforms June 2025); 93% of deals include NWC adjustment + 90-day median true-up; 5 named 8-K extractions (Owens & Minor/Rotech $1.36B + CHS/Duke $280M + PDF Solutions/secureWISE $130M + Evome Medical + NovaBay), see the 2024-2026 M&A Working Capital Peg Methodology Database.

Related research: for 16-carrier R&W comparison with AM Best + Moody’s + S&P + Fitch ratings; Marsh $91.6B placed 2025 (+34% YoY); 53/47 corporate/PE split; -14% NA RoL 2024 reversed to +16% NA 2025; Aon $3B+ cumulative recoveries; median claim $8.2M 2025 vs $5.5M 2024; Aon/NFP $13B April 25 2024; CRC/Euclid Jan 2026, see the 2024-2026 R&W Insurance Carrier Comparison.

Related research: for SBA 7(a) FY2025 $37.3B total / $8.29B acquisition segment; Live Oak Bank NYSE: LOB #1 at $2.8B / 2,280 loans +44% YoY; Newtek #2 at $2.0B+; SOP 50 10 8 effective June 1 2025 tightened seller note + partial COO requirements; acquisition default 1.93% vs 2.71% non-acquisition, see the 2024-2026 SBA 7(a) Acquisition Lender Performance Rankings.

Related research: for 50-state non-compete enforceability map post-FTC vacatur (16 CFR Part 910 removed Feb 12 2026 via 91 Fed Reg 6712); 5 total ban states for employees (CA SB 699 + AB 1076 Jan 1 2024 + MN § 181.988 + ND + OK + DC); Sunder Energy Del Dec 10 2024 blue-pencil refusal; U.S. v. Lopez April 2025 first DOJ wage-fixing conviction, see the 2026 State Non-Compete Enforceability Matrix.

Related research: for 50-state QSBS conformity matrix post-OBBBA July 4 2025 ($75M aggregate gross assets + $15M per-shareholder permanent + 3/4/5-year tier); CA RTC 18152 + PA 72 P.S. 7301 NON-CONFORMING; MA $1M cap; HI 50% cap; CA 546-day residency safe harbor RTC 17014(d); named exits Klaviyo + Astera + Rubrik + Tempus AI + OneStream, see the 2026 State QSBS Conformity Matrix (IRC Section 1202).

Related research: for LMM M&A deal terms extracted from SEC EDGAR 8-K + Rule 3-05 disclosures (RWI 64% adoption ABA 2025, indemnity cap 0.25% with RWI, earnout 18%, double-scrape 56%, Marsh $91.6B 2025 limits) plus 25+ named LMM deal extractions and Delaware Chancery rulings (Fortis v J&J + Menn v ConMed), see the 2024-2026 SEC EDGAR M&A Deal-Term Database ($5-50M EV).

What is the typical all-in closing cost as a percentage of EV on a $25 million enterprise value transaction?

Combined buyer plus seller closing costs on a typical $25 million EV LMM transaction with PE buyer, Big 4 QofE, R&W placement, and 50 percent LTV debt financing run approximately 8.3 percent of EV, or about $2.07 million. The seller side runs higher (5.6 percent) than the buyer side (2.7 percent) because the advisor success fee at the LMM clusters at 4 to 6 percent of EV. See Section 15.2 for full breakdown.

How much does a quality-of-earnings (QofE) report cost on a $50 million EV deal?

QofE on a $50 million EV deal typically runs $50,000 to $95,000 with a median of approximately $72,000, per DueDilio, Mainshares, Eton, and Rejigg. Big 4 list rates run higher; mid-tier national accounting firms and LMM specialists run lower. See Section 6.4.

What is the 2026 HSR filing fee schedule?

The 2026 HSR filing fee schedule, effective February 17, 2026, sets six tiers from $35,000 (for transactions $133.9M to $179.4M) to $2,460,000 (for transactions $5,555.0M and above) per the FTC notice. The size-of-transaction threshold for reporting in 2026 is $133.9 million, up from $126.4 million in 2025. See Section 10.2 for full schedule.

What is the current R&W insurance premium as a percentage of limit?

R&W premiums in 2026 cluster at 2.5 to 3.0 percent of limit for clean transactions and 3.0 to 4.0 percent for harder-to-place sectors (healthcare, financial services, distressed). The market dipped to 2.0 to 2.5 percent in late 2024 and firmed back through 2025-2026 per WTW, Marsh, and Horton Group. Retention is typically 0.5 percent of EV with drop-downs after 12 months. See Section 7.

Is the Lehman formula still the standard M&A advisor fee structure?

The original 5/4/3/2/1 Lehman formula is essentially obsolete. The 2024-2026 standard is one of the Modified Lehman variants (Double Lehman 10/8/6/4/2 or 3-3-2-1-1) or a tiered hurdle structure that pays the advisor escalating percentages above defined price thresholds. See Section 8.2.

What is the median sell-side advisor success fee on a $100 million EV deal?

Sell-side advisor success fees on $100M to $250M EV deals cluster at 1.5 to 3.0 percent with a median around 2.2 percent per First Page Sage, M&A Community, and the Firmex / Axial fee guide. At the $100 million benchmark point in this report, a 3 percent fee equates to $3.0 million in advisor expense. See Section 8.5.

Why does the all-in closing cost percentage decline so sharply with deal size?

Several large cost buckets (HSR filing fees, escrow agent base fees, R&W underwriting fees, paying agent setup, advisor minimums, QofE minimums) are essentially fixed in dollar terms, while the variable buckets (legal, QofE, advisor success fees) scale sub-linearly with deal size. A $5 million EV transaction that bears a $25,000 QofE, $60,000 in legal fees, a $250,000 minimum sell-side advisor fee, and $30,000 in other diligence is already at 7.3 percent of EV before R&W, tax structuring, or financing costs. See Section 3.4.

How much does Houlihan Lokey generate in M&A advisory revenue?

Houlihan Lokey reported total revenue of $2.39 billion for fiscal year 2025 (year ended March 31, 2025), with Corporate Finance (M&A advisory) up 38 percent year over year and representing 64 percent of firm revenue per the Houlihan Lokey FY2025 Form 10-K. Houlihan ranked #1 US M&A advisor by deal count for ten consecutive years through 2025. See Section 8.1.

What is the adoption rate of representation and warranty insurance (RWI) in private M&A?

The ABA 2025 Private Target M&A Deal Points Study found 63 percent of analyzed deals referenced RWI, up from 55 percent in the 2023 study. K&L Gates confirms RWI is now the default in middle-market PE-led transactions. Carriers have moved downmarket and are willing to write limits below $5 million on sub-$25 million EV transactions per Cooley. See Section 7.4.

What is the largest cost reduction lever available to sellers in 2024-2026?

For sellers, the single largest lever is negotiating a no-seller-indemnity / RWI-only structure that eliminates the 0.5 to 2.0 percent of EV typically held in indemnity escrow for 12 to 24 months. The buyer absorbs the R&W premium (often shared) and self-insures the retention. In competitive sale processes the seller now expects this structure as default per Gallagher 2026 and CBIZ. See Section 16.1.

What total US PE middle-market deal value did Pitchbook record in 2025?

Pitchbook recorded US PE middle-market deal value of $410.7 billion in 2025 across an estimated 4,018 transactions, up 8.5 percent year over year by value and 16 percent by deal count. Full-year US PE deal value reached $1.2 trillion, the second-highest total on record after 2021. See Section 17.7.

What are typical legal fees on a $100 million EV transaction?

Buyer counsel on a $100 million EV transaction typically runs $250,000 to $600,000 and seller counsel $175,000 to $450,000, for a combined legal total of $425,000 to $1.05 million. Tier-1 firms (Wachtell, Sullivan, Cravath) run higher; Tier-4 firms (Foley, Faegre, Polsinelli) run lower. See Section 4.8.

How long does an HSR-reportable transaction take to close?

The standard HSR initial waiting period is 30 days from filing acceptance (15 days for cash tender offers and bankruptcy 363 sales). If either the FTC or DOJ issues a Second Request, the waiting period extends by an additional 30 days from substantial compliance. Substantial compliance can take 60 to 180 days depending on document scope. See Section 10.1.

What share of total closing cost goes to the investment bank or M&A advisor?

The investment bank or M&A advisor success fee typically represents 40 to 55 percent of total closing cost at the LMM, declining proportionally at higher EV. At $25 million EV with a 5 percent advisor fee, advisor cost of $1.25 million represents 60 percent of the $2.07 million all-in total. At $500 million EV with a 1.1 percent advisor fee, advisor cost of $5.5 million represents 30 percent of the $18.11 million all-in total. See Sections 8 and 15.

Where can I find disclosed M&A closing cost data in SEC filings?

The most useful public sources for itemized transaction-cost disclosure are: (1) Form S-4 fee tables filed in public-to-public stock mergers; (2) bankruptcy court fee applications in Chapter 11 363 sales filed in Delaware and SDNY; (3) SPAC business combination 8-Ks and proxies; and (4) selected acquirer 10-Q MD&A sections disclosing acquisition-related expenses. Private-buyer LMM and MM transactions are generally not disclosed. See Section 18.

24. About the Author

The CT Acquisitions Research Desk publishes citation-grade benchmarks on US lower-middle-market and middle-market M&A, with deep coverage of the legal, tax, R&W, advisor fee, HSR, working capital, QSBS, non-compete, SBA financing, and SEC deal-term landscape. Every numeric and dated claim in our reports carries a primary or named secondary source. Where data is unavailable, the section is explicitly labeled GAP. Our methodology cross-references the ABA M&A Committee Deal Points Studies, SRS Acquiom Deal Terms Studies, BTI Consulting Premium Rate research, FTC HSR releases, WTW / Marsh / Gallagher R&W marketplace updates, and SEC EDGAR transaction filings. For questions or to suggest corrections, contact the CT Acquisitions Research Desk.

Last updated: June 22, 2026.