Top Quality of Earnings Firms for M&A Deals

The top quality of earnings firms are the Big Four (Deloitte, PwC, EY and KPMG), followed by global networks such as BDO, Grant Thornton, RSM, Baker Tilly, Crowe and Forvis Mazars, plus advisory specialists like Alvarez & Marsal and FTI Consulting.

A quality of earnings (QoE) report tests whether a target’s reported EBITDA is a reliable base for the price. For a buyer or lender, the right QoE firm turns a seller’s adjusted EBITDA into a number you can defend at investment committee and in the purchase agreement.

This list ranks 13 firms. Within each group, firms are ordered by their most recently reported annual revenue as published by each firm up to 10 November 2026.

How this list is ranked

Revenue is the one measure every firm publishes on the same basis, so it is the ranking measure. It shows scale, which drives how many deal teams, sector specialists and offices a firm can put on your transaction.

Keep three points in mind when you read the numbers:

• Fiscal years differ: Deloitte’s year ends in May, PwC’s and EY’s in June, KPMG’s, BDO’s and Grant Thornton’s in September, and most others in December or August.
• Network revenue covers every service line: audit, tax and consulting sit in the same total as transaction services.
• QoE is only one part of deal work: a firm with a smaller total can still have the strongest team in your sector or deal size.

Comparison of the top quality of earnings firms

The table gives each firm’s latest reported revenue and one deal-relevant figure from the same disclosure.

The Big Four

The Big Four run the largest transaction services teams and are the default choice on large-cap buyouts, carve-outs and cross-border deals. Lenders on big leveraged loans often expect to see one of their names on the QoE.

1. Deloitte

Deloitte reported revenue of $74.5bn for the year to 31 May 2026, up 5.7% in US dollars. Its QoE work sits in Strategy, Risk & Transactions, which grew 4.4% in local currency. Deloitte had nearly 500,000 people at the time of the announcement.

2. PwC

PwC reported gross revenue of $60.2bn for the year to 30 June 2026, up 5.7% in US dollars. Advisory brought in $25.8bn, up 4.7% in US dollars. PwC has more than 360,000 people across over 130 countries and territories.

3. EY

EY reported revenue of $57.0bn for the year to June 2026, up 4.7% in local currency. Transaction work runs through EY-Parthenon, which earned $6.8bn and grew 7.4% in local currency. That is the only Big Four deals business with its own published revenue line.

4. KPMG

KPMG reported revenue of $39.8bn for the year to 30 September 2025, up 5.1% in local currency. Advisory earned $16.4bn, up 2.9% in local currency. KPMG had 276,030 people at the year end and published these figures in December 2025.

Global accounting networks

These networks are the usual choice for middle-market and lower middle-market deals. On a smaller transaction, a Big Four team can be more firepower than the deal needs, and a network firm’s partner is often closer to the work.

5. BDO

BDO reported revenue of $11bn for the year to 30 September 2025, excluding alliance firms, up 4% in US dollars. Its advisory business grew 4%. The network has over 94,900 people in 870 offices.

6. Grant Thornton

Grant Thornton reported record revenue of $8.5bn for the year to 30 September 2025, up 5.9% in US dollars. Advisory grew 4.7% to $3.0bn, or 35.1% of the total. The network has about 80,000 people.

7. RSM

RSM reported revenue of $7.7bn for 2025, up 4% on a comparable basis, according to its March 2026 results release. Consulting earned $2.9bn, with fee income up 7%. RSM has 56,000 professionals.

8. Baker Tilly

Baker Tilly International reported record revenue of $6.8bn for 2025, up 21.3%, in its January 2026 announcement. Advisory revenue grew 16%. The network has 50,443 people in 147 territories.

9. Crowe

Crowe Global reported revenue of $6.5bn for 2025, up 12%, according to its February 2026 release. It has about 46,000 professionals in over 150 countries. Growth was fastest in Europe at 21%.

10. Forvis Mazars

Forvis Mazars reported combined revenue of more than $5.7bn for the year to 31 August 2025, up 11%, in its February 2026 results. Advisory, which includes financial advisory, made up 21% of revenue. The network covers over 100 countries and territories.

Advisory specialists and US-listed firms

This group suits buyers who want senior, deal-focused teams, or who expect the QoE to feed into restructuring, disputes or post-closing work.

11. FTI Consulting

FTI Consulting reported 2025 revenue of $3.79bn, up 2.4%. Its Corporate Finance segment earned $1.55bn. FTI had more than 8,100 employees in 32 countries and territories at the end of 2025.

12. CBIZ

CBIZ reported 2025 revenue of $2.76bn in its 2025 annual report on Form 10-K, a total that includes the Marcum business it combined with. The Financial Services segment earned $2.30bn, or 83.4% of the total, and the 10-K lists transaction advisory among its services. CBIZ has more than 9,500 team members.

13. Alvarez & Marsal

Alvarez & Marsal is privately owned and does not publish revenue, so it sits last in its group. In December 2021, its Global Transaction Advisory Group had over 600 professionals in 29 offices. A&M called it the largest transaction advisory practice outside the Big Four. The group serves private equity, sovereign wealth funds, family offices and corporate buyers.

How do you choose a quality of earnings firm?

Match the firm to the deal first, then to the people. Use these criteria:

• Deal size: large-cap and syndicated deals usually need a Big Four name for lenders. Middle-market deals are well served by the global networks.
• Sector depth: ask for three recent QoE reports in your sector and the names of the people who led them.
• Team staffing: confirm which partner and manager will be on the deal day to day. The brand on the cover counts for less than the manager doing the work.
• Scope: agree whether the work covers net working capital peg, net debt items, proof of cash and run-rate adjustments. These feed straight into the purchase agreement.
• Conflicts and independence: check that the firm does not audit the target or advise the other side.
• Lender and insurer acceptance: ask your debt providers and your reps and warranties insurer which firms they accept.

For a seller, a sell-side QoE from a recognised firm before launch cuts the time buyers spend on diligence and reduces the risk of a price chip after the letter of intent. Our guide to sell-side vs buy-side due diligence sets out who commissions what.

What a QoE firm actually delivers

Whichever firm you pick, the core output is the same. A strong report gives you:

• Adjusted EBITDA bridge: from reported EBITDA to diligence-adjusted EBITDA, with each adjustment explained.
• Normalised net working capital: a monthly average that becomes the peg in the purchase agreement.
• Net debt and debt-like items: deferred revenue, unpaid bonuses, tax liabilities and other items that reduce equity value.
• Revenue and margin analysis: customer concentration, churn and price versus volume.

Our explainer on the quality of earnings report in M&A walks through each section. For the wider diligence picture, read our practical guide to operational due diligence and how reps and warranties insurance relies on the QoE. If you are sizing advisers for a mid-sized sale, our list of the best middle market investment banks covers the sell-side banks that usually run these processes.

FAQ

Who are the biggest quality of earnings firms?

Deloitte, PwC, EY and KPMG are the biggest by revenue. Deloitte reported $74.5bn for the year to May 2026, PwC $60.2bn and EY $57.0bn for the year to June 2026, and KPMG $39.8bn for the year to September 2025. All four run dedicated transaction services teams.

Do I need a Big Four firm for a QoE?

You need one when lenders, co-investors or insurers expect it, which is common on large-cap and syndicated deals. On middle-market deals, BDO, Grant Thornton, RSM, Baker Tilly and similar networks are widely accepted. Ask your debt providers which firms they accept before you sign an engagement letter.

What is the difference between buy-side and sell-side QoE?

A sell-side QoE is commissioned by the seller before launch to support the asking EBITDA and reduce price chips. A buy-side QoE is commissioned by the buyer to test that number independently. Many buyers still commission their own report even when a sell-side QoE exists.

Which firms suit middle-market private equity deals?

The global networks are the usual fit. RSM, Grant Thornton, BDO, Baker Tilly and CBIZ all run transaction advisory teams for middle-market sponsors. Advisory specialists such as Alvarez & Marsal and FTI Consulting suit deals where you want senior deal teams or restructuring experience.

Conclusion

The top quality of earnings firms by revenue are Deloitte, PwC, EY and KPMG, followed by BDO, Grant Thornton, RSM, Baker Tilly, Crowe and Forvis Mazars, with FTI Consulting, CBIZ and Alvarez & Marsal as specialist options. Pick the firm whose named team has done recent deals in your sector at your size, and check lender acceptance before you engage.

P.S. To see how QoE findings show up in real deal materials, browse the Investment Banking Decks Database. Our Premium Resources have more tools you may find useful, and the Private Equity Bros newsletter brings you weekly finance updates and the latest financial reports.

Sources

• Deloitte reports FY2026 revenue
• PwC announces FY26 global financial performance
• EY global revenue increases 4.7% to US$57b for fiscal year 2026
• KPMG delivers 5.1% rise in global revenue
• BDO reports growth in global annual revenues
• Grant Thornton grows global revenues to a record USD8.5 billion
• FTI Consulting Reports Fourth Quarter and Full Year 2025 Financial Results