M&A Advisor Fees in 2026: Retainers, Success Fees, Lehman

M&A advisors get paid three ways: a retainer while they prepare and market your company, a success fee at closing, and a minimum fee that floors it. For a mid-market business the success fee runs 2–8% of enterprise value and slides down as the deal grows (Morgan & Westfield); most retainers are credited against it. On a $20M sale that's $600K–$1M depending on the scale. Below: the arithmetic, the Lehman formula priced at three deal sizes, and when a success fee is worth paying.

Sell-side advisors charge three things: a retainer while they prepare the company, a success fee of 2–8% of enterprise value that falls as the deal grows, and a minimum fee that floors it (Morgan & Westfield). Most advisors credit the retainer against the success fee (Axial). In our work on 50+ M&A transactions, the structure matters less than what it buys: preparation, competitive tension, a clean close.

Full disclosure: Waveup does M&A preparation on a retainer with no success fee. We also send founders to banks and brokers when that's the better fit, and this article says when. Treat every structure below as incentive design, not a price tag: a success-only model pays the advisor to close any deal, and firms running it don't close a greater share of deals, just a greater number (Axial).

How do M&A advisors make money?

Four fee components dominate: a retainer, monthly or one-time, that funds preparation and marketing; a success fee, a percentage of enterprise value paid at closing; a minimum fee that floors it; and, in a minority of letters, break-up or progress fees. In Axial's 2026 survey, 71% of advisors charge an upfront fee and most credit it against the success fee (Axial). The success fee is where the money is.

1. The retainer (work fee, engagement fee). Non-refundable, monthly or lump sum, usually capped. Roughly a third of advisors now charge nothing upfront, a share that has grown sharply since 2024, and the rest split between a one-time engagement fee and a monthly retainer (Axial's fee guide); the survey table below has the split. It buys commitment on both sides, and it shouldn't exceed 15% of the total expected fee (Divestopedia).

2. The success fee. A percentage of enterprise value paid at closing, on deal value rather than your proceeds: debt the buyer assumes cuts your payout but not the fee base (Axial). Lehman-style declining scales remain the most common structure, flat percentages are gaining ground fast, and between them the two cover most engagement letters (Axial). A minority of firms use accelerator scales, which rise above a target price (Axial).

3. The minimum fee. A floor on the success fee whatever the final price. At most boutiques it starts around $50K and can reach a quarter of a million (Morgan & Westfield). Law-firm guidance for mid-market mandates puts it higher still (Dorsey); the table below has both ranges. We run the maths on a sub-$10M sale further down.

4. Break-up, progress and abort fees. Some letters charge you for withdrawing the company or when a milestone such as a signed LOI is reached. Over a quarter of firms in Axial's 2026 survey charge a break-up fee (Axial). Most business-broker agreements go further and demand the full fee if you withdraw the listing (Morgan & Westfield). Decline fees triggered by non-binding term sheets; deals die after LOI all the time (Axial).

What is the Lehman formula, and what does it cost at $5M, $20M and $100M?

The Lehman formula is a declining success-fee scale: 5% of the first million of enterprise value, a point less on each of the next three, and 1% of everything above (Divestopedia). Inflation made it too thin, so advisors now quote Double Lehman, which doubles every tier, or Modern Lehman, which starts higher and slides more slowly. The table below prices all three at $20M.

The original scale was built for financing engagements and became the M&A template in the 1970s and 80s (Axial). Inflation has since made it unworkable, so it survives mainly with finders. Double Lehman doubles every tier. Modern Lehman starts at 10% and steps down a point per million before flattening out above the first seven million, and it is now the most common form among mid-market specialists (Wikipedia). Brokers quote a variant close to Double Lehman, sometimes with a higher first tier (Morgan & Westfield); on a $5M sale it comes to about $300K. The table sets the four side by side and prices the Lehman versions at three deal sizes.

At $5M the original formula is below what any serious advisor will work for, so brokers and small boutiques quote Double or Modern Lehman. At $100M the opposite problem appears: Modern Lehman lands above the range Divestopedia calls reasonable for deals of that size (Divestopedia). Larger mandates therefore switch to a Modified Lehman, which charges 2% of the first $10M and less on the balance, or to a flat percentage (Axial). The scale you're offered tells you which bracket the advisor thinks you're in.

What is the average fee for an M&A advisor?

There's no single average because the percentage falls as the deal grows. Divestopedia's rule of thumb runs from high single digits on the smallest advised sales to low single digits at the top of the mid-market (Divestopedia); the full ladder is in the table below. In our work, a $10M sale usually carries 5–7% all-in once the minimum fee bites, and the rate roughly halves at nine figures.

M&A advisor fees in 2026, in short. Structure has barely moved: Axial's 2026 M&A Fee Guide, a Q2 survey of 331 advisors, finds Lehman-style scales still the most common success-fee structure, flat percentages gaining ground, and most advisors charging an upfront fee that they credit at close (Axial); the survey table in the first section has the figures. Level slides with size: Divestopedia's rule of thumb runs from high single digits on small deals to low single digits above $50M (Divestopedia), and the table below turns each bracket into dollars. Around the success fee sit a retainer, a minimum fee and a tail period, tabulated by provider type in the first section. Buy-side mandates cost less (Dealroom). On formulas, Original Lehman survives mainly with finders; Double and Modern Lehman are what mid-market advisors actually quote (Wikipedia).

Two cross-checks. FirstPageSage segments by EBITDA rather than enterprise value and reaches a similar ladder, with retainers over the whole process in the tens of thousands to low six figures (FirstPageSage). Axial's engagement-letter guide adds that flat fees on the smallest deals run to double digits, while above $50M the flat rate can fall to 1.5% (Axial). Both sets of figures, and our own all-in observations, are in the table below. Two advisors quoting the same company can sit two points apart, which on a $20M sale is $400K. For the enterprise value itself, see our exit multiples by industry guide.

How much do M&A advisors charge upfront, and what does a minimum fee do to a $3M–$8M sale?

Boutique retainers are small next to the success fee: a few thousand dollars to $50K+ in total (Morgan & Westfield), more at a bank; the table in the first section has the ranges by provider. In our work, most boutique retainers land at $5K–$25K a month, and on a sale under ten million the minimum fee, not the percentage, sets the real price.

Retainers fund the weeks before any buyer sees the company: financial clean-up, the confidential information memorandum, the model, the buyer list. They're priced on risk: the wider the gap between your price expectation and the market, the higher the work fee, and banks with heavier overheads charge more than boutiques (Divestopedia). Expect monthly payments for no more than 12 months, capped at an agreed level (Divestopedia).

Minimum-fee maths on a $3M–$8M sale. Take a 5% success fee with a $250K minimum. At the low end of that range the floor, not the percentage, sets the bill, and your effective rate is well above the headline; at the high end the floor never bites. Now raise the minimum to $500K, well inside the range Dorsey reports on mid-market mandates (Dorsey). Every outcome under $10M now costs the same, and at the low end your effective rate is more than three times the headline. The table shows the arithmetic. Under that threshold, negotiate the minimum harder than the percentage.

Business brokers are the exception: straight commission, a minimum in the low tens of thousands and no retainer, which is why they dominate below $5M (Morgan & Westfield). The trade-off is incentive. Straight commission rewards the fastest sale rather than the best one, and brokers price the listings that never sell into the ones that do (Morgan & Westfield).

Buy-side vs sell-side fees: who pays, and what's in the engagement letter?

Each side pays its own advisor: whoever signs the engagement letter owes the fee (Nolan & Associates). Sell-side fees come out of your proceeds at closing. Buy-side mandates cost less as a percentage, typically 2–3% in the lower mid-market and less above it, with retainers credited against the success fee (Dealroom). Either way, the tail clause and the transaction-value definition decide what you actually owe.

Buy-side. Buyers hire advisors to source targets, run diligence and negotiate. Retainers run monthly over a search that typically lasts six months to a year, and success fees average lower than sell-side (Dealroom): there's no auction to run. The table has Dealroom's ranges. A strategic acquirer doing a bolt-on in the $5M–$20M range often skips the banker and buys modular support instead, a valuation, a due diligence review, an integration model, which is the shape of the work behind the two bolt-on acquisitions in our lithium-battery roll-up case.

The tail clause. If the company sells after the engagement ends, to a buyer the advisor introduced, the fee is still owed. Two years is a fairly standard ask (Axial). Tails frequently cover only specified buyers (Venable). Negotiate three things. Length: Taft routinely limits it to 12 months, sometimes half that (Taft Law). Scope: only buyers actually contacted, with a written list delivered within 10 days of termination (Dorsey). And a carve-out if you terminate for cause (Axial).

A US wrinkle. Anyone paid according to the size or outcome of a securities transaction, including finding buyers for a business sold as stock, may need to register as a broker-dealer (SEC). Since March 29, 2023, a federal exemption, Exchange Act Section 15(b)(13), has covered M&A brokers on sales of private companies below a size threshold, if the buyer takes control and is active in management, with no relief from state registration (Sidley). The threshold is under $25M of EBITDA or under $250M of revenue. Ask any US advisor which side of that line they're on.

Are M&A advisor fees worth it?

Usually, for a single reason: a run process changes the buyer's behaviour, not just your paperwork. Competitive tension moves the price, structure moves what you actually receive, and preparation removes the re-trade. We've seen a $25M all-cash offer net founders more than a $35M deal once the rollover and earnout were modelled. A 3% fee is small next to a re-trade in diligence.

Start with the market's own diagnosis. Advisors in Axial's 2026 survey named the gap between seller expectations and buyer pricing discipline as the main obstacle to closing, made wider by sellers substituting AI-generated numbers for a real valuation (Axial). In our work the gap between a founder's valuation expectation and what the market supports is often 2–3×. Seven founders in ten underestimate what buyers ask for in diligence. A third-party valuation built from DCF and comparables closes the first gap before a buyer exploits it.

What a fee actually buys, in order of value:

1. Competitive tension. Several qualified buyers on the same clock. Fees on a negotiated single-buyer sale are typically lower because there's no auction to run (Divestopedia), which tells you where the value sits.
2. Structure. Liquidation preferences, escrow holdbacks, working-capital adjustments and earnouts decide the take-home number; an advisor who models the waterfall before the LOI beats one who negotiates the headline after it.
3. Re-trade protection. Problems surfacing mid-diligence hand the buyer leverage to cut price. A data room indexed against the buyer's list before you go to market removes most of them; in our fundraising work that indexing cuts Series A diligence time by about 30%.
4. Time. A full sell-side process runs six to twelve months industry-wide; Waveup clients close about 70% faster than founders and sellers running alone (median, 2024–2025 cohort).

The counter-argument is real. If you already have the buyer, a scaled success fee pays for tension that doesn't exist, and a fixed fee or hourly structure fits a negotiated sale better (Divestopedia). And a lower percentage is a shallow win if the advisor can't get the higher offers (FirstPageSage). For the process itself, read how to sell your startup; for who runs it at each size, best M&A advisors for startups.

How does Waveup charge for M&A work, and when are we the wrong choice?

Waveup's M&A preparation is priced from a $10K retainer with no success fee on the advisory work: CIM, financial model, valuation, data room and buyer list, delivered in four to eight weeks. Our sweet spot is $5M–$100M deals; Olena Petrosyuk (ex-Lazard, JP Morgan) leads, and we've supported more than fifty transactions. If you need a bank for the auction or a broker for a small local sale, we'll say so.

The model is deliberately a retainer, not a percentage. Preparation is where most of a sale's value is created or lost, and a success-fee advisor's money arrives at closing, so the pull is toward thin materials and a fast launch. A Waveup M&A engagement does the opposite: Olena writes or reviews every CIM (here's a CIM example), the financial model is driver-based and built to survive a quality-of-earnings review, the valuation is defended against comparables, and the data room is indexed against an 80+ item diligence checklist. You then run the process with us, with your bank, or alone, and keep every point of success fee you didn't sign away.

When we're the wrong choice, plainly:

• You want one firm to run the auction and negotiate the purchase agreement. That's a full-service bank or boutique on a retainer-plus-success-fee letter; above $50M their buyer relationships are worth the couple of points they charge.
• Your business is under $3M and mostly local. A broker on straight commission with a small minimum is the efficient answer (Morgan & Westfield).
• You only want to pay on success. We don't do that on advisory; nearly a third of advisors in Axial's 2026 survey do (Axial). Go in clear-eyed about the incentive.
• Your problem is timing, not materials. The ideal engagement window is 12–24 months before close. Three weeks from a signed LOI, you need a deal lawyer and a quality-of-earnings provider, not a CIM.