How M&A advisor fees are structured
Most M&A advisors combine two components: a retainer paid during the engagement, and a success fee paid at closing. The retainer covers the advisor's time and out-of-pocket costs during a process that can run six months or longer; the success fee is what actually aligns their incentive with getting you the best outcome.
Exact figures vary significantly by deal size, industry, and firm. There's no single published rate card across the industry, and any firm quoting you a number before understanding your business is guessing. Treat everything below as general orientation, not a quote.
Total advisor cost (retainer plus success fee) typically lands somewhere between 1% and 10% of transaction value, with smaller deals landing at the higher end of that range as a percentage, the advisor's work doesn't shrink proportionally just because the deal is smaller.
Retainers
A retainer is a recurring or upfront fee paid to the advisor during the engagement, independent of whether the deal closes. It typically covers process costs, preparing marketing materials, running outreach, managing data rooms, and signals that you're a serious client, not just gathering opinions.
| Deal Size | Typical Monthly Retainer | Notes |
|---|---|---|
| Under $10M | $5,000–$15,000/mo | Sometimes waived or reduced, credited against the success fee. |
| $10M–$50M | $10,000–$25,000/mo | Most common range for lower-middle-market engagements. |
| $50M+ | $25,000+/mo, or a flat upfront fee | Larger firms may charge a substantial non-refundable engagement fee instead. |
These figures are general market ranges for orientation only, confirm actual terms directly with any firm you engage.
Success fees & the Lehman formula
The success fee is the advisor's main compensation, paid as a percentage of transaction value at closing. The most common framework, even when heavily modified in practice, traces back to the "Lehman formula," a sliding scale that charges a higher percentage on the first tranche of value and less on each tranche above it.
| Transaction Value Tranche | Classic Lehman Fee |
|---|---|
| First $1M | 5% |
| Second $1M | 4% |
| Third $1M | 3% |
| Fourth $1M | 2% |
| Everything above $4M | 1% |
The original Lehman scale was designed decades ago and its dollar thresholds haven't kept pace with deal sizes since, most advisors today use a "modified Lehman" with higher percentages, different tranche sizes, or a flat blended rate instead. Ask specifically which version applies to your deal.
The double Lehman formula
A "double Lehman" simply doubles each tranche's percentage, 10%, 8%, 6%, 4%, 2%, and is more common on smaller transactions, where the classic scale's dollar thresholds would otherwise leave an advisor underpaid relative to the actual work involved. Some firms use a "triple Lehman" on very small deals for the same reason.
There's no universal standard, the specific multiple, tranche sizes, and minimum fee are all negotiated per engagement. What matters is understanding which structure you're being quoted and how it compares to what similar-sized deals typically pay.
What's actually negotiable
- 01
Minimum fee
Most engagement letters specify a minimum success fee regardless of final deal size, this protects the advisor if the deal closes smaller than expected, but the floor itself is negotiable.
- 02
Retainer credit
Many firms will credit some or all of the retainer paid against the eventual success fee, confirm whether this is offered before you sign.
- 03
Tail period & tail fee
Most engagements include a "tail", a period after the engagement ends during which the advisor is still owed a fee if you close with a buyer they introduced. Tail length (commonly 6–24 months) and scope are both negotiable.
- 04
Expense caps
Out-of-pocket expenses (travel, data room costs, legal review) are often billed separately, ask for a cap or pre-approval threshold in writing.
Fee red flags
- ✕
A quote before any real diligence on your business
A firm proposing specific fee terms before reviewing your financials is negotiating blind, or not being fully transparent about how the number was reached.
- ✕
No minimum fee disclosed upfront
If the engagement letter is vague about the minimum fee, ask directly, this number matters enormously if your deal closes below initial expectations.
- ✕
An unusually long or broad tail provision
A tail longer than 24 months, or one that covers buyers the advisor never actually introduced you to, disproportionately favors the advisor. Push back.