What Business Owners Pay a Broker or M&A Advisor: 2026 Fee Guide + Calculator

The fee you pay a business broker or M&A advisor is the most misunderstood cost in any business sale. Owners routinely overestimate it on small deals and underestimate it on large ones. Buyers assume they pay nothing — and are occasionally surprised to find they pay indirectly, or directly if they have hired their own buy-side advisor.

This guide covers every fee structure currently used in US business brokerage and M&A advisory — Lehman formula, Double Lehman, Modified Lehman, flat percentage, and retainer-plus-success — with a live calculator that shows your specific cost at any deal size. Plus: who actually writes the cheque, when fees are due, what is genuinely negotiable, and the red flags that should make you walk away from an engagement.

1. Why Understanding the Cost Matters

The fee reduces your net proceeds as an owner — directly. On a $1.5M business with a 10% commission, the fee is $150,000, leaving $1,350,000 before tax. It is the second-largest cost of the transaction after the capital-gains liability itself.

As a buyer, the fee matters because it sits inside the seller's asking price. A seller who needs $1.5M net after a 10% commission will list at roughly $1.67M. The same seller using a flat-fee broker charging $40,000 can list at $1.54M for the same net outcome. Understanding the fee structure helps a buyer see how much of the price reflects advisory cost rather than business value.

The structure also affects tax. A $25,000 retainer paid upfront is treated differently from a $25,000 credit against the success fee at closing. Discuss the tax treatment of the fee with your accountant before signing.

2. Who Pays a Business Broker?

3. Sell-Side Fee Structures Explained

Flat percentage — main street standard

A single percentage applied to the total transaction value. Main street businesses (under $1M) typically pay 8–12%, with most brokers charging 10%; the rate steps down for larger deals (BizBuySell; IBBA). It is simple and easily understood, but less equitable across sizes — 10% on $100K ($10K) barely covers the broker's time, while 10% on $5M ($500K) can exceed market rates for the work involved.

Minimum fees

Almost every listing agreement includes a minimum success fee — typically $10,000–$25,000 — regardless of deal size (Morgan & Westfield). This protects the broker on small deals where the percentage alone would be too low. A $20,000 minimum on a $150,000 sale is a 13% effective rate, which is legitimate: representing a $150K business takes nearly the same work as a $500K one.

The Lehman formula (5-4-3-2-1)

The original Lehman Brothers structure, from the 1970s, still used as a reference point. It charges 5% on the first $1M, 4% on the second, 3% on the third, 2% on the fourth, and 1% above $4M. On a $3M deal: $50K + $40K + $30K = $120,000 (4.0% effective). Designed for $1M–$10M deals; rarely used as-written below $1M or above $10M today (Founders Advisors).

The Double Lehman formula (10-8-6-4-2)

Doubles each Lehman rate. Common for main street and smaller LMM deals where Lehman rates would produce a fee too small to justify the work. Worked example: a $5M deal = $100K (10% on the first $1M) + $80K + $60K + $40K + $20K (2% above $4M) = $300,000 (Morgan & Westfield). This is the basis for the "10% on small deals" convention.

Modified Lehman (3-3-2-1-1) — the current LMM standard

The most common structure for deals above $5M. Larger tranches, lower percentages: 3% on the first $5M, 3% on $5M–$10M, 2% on $10M–$20M, 1% above $20M. On a $10M deal: $150K + $150K = $300,000 (3.0% effective). On a $20M deal: $500,000 (2.5% effective) (Auxo Capital Advisors).

Retainer (work fee) + success fee

For LMM deals ($5M+), advisors charge a monthly retainer — commonly $10,000–$50,000/month over a 3–6 month engagement — on top of the success fee, usually credited against it at closing (Auxo Capital Advisors). The retainer covers significant upfront work and screens out owners who are not serious. It is also called a work fee, engagement fee, or upfront fee (Founders Advisors).

4. The Business Broker & M&A Advisor Fee Calculator

5. What a Buyer Pays

The "who pays" question has a second side: the buyer. It is a smaller share of transactions, but it is the same cost question — what does hiring representation cost the person who hires it — so it belongs here, kept separate from the seller-pays case above.

At main street sizes, the buyer usually pays nothing directly

At $100K–$2M, buyers almost never pay a direct broker fee. The listing broker represents the seller, is paid from the seller's proceeds, and may still help the buyer understand the deal — at no direct charge. If the broker assists both sides (dual agency), the seller typically still pays the full commission.

Buy-side advisory at LMM and above ($5M+)

For deals above $5M — private-equity buyers, corporate acquirers, search funds — buyers frequently hire their own buy-side advisor to find targets, manage the process, and negotiate exclusively on their behalf. Typical cost: a monthly retainer (deal-size dependent) plus a success fee of 0.5%–2.0% of transaction value at closing, generally lower than the sell-side fee (DealRoom). Some buy-side advisors work success-only where the search scope is narrow.

The "no win, no fee" buy-side search

Success-fee-only buy-side mandates exist but are uncommon. Advisors taking a pure success fee on a search are either very confident in the pipeline or accepting a lower fee in exchange for removing the buyer's downside. Most established buy-side advisors require at least a minimum retainer, because acquisition searches often run 12–24 months and the engagement needs to be funded regardless of outcome.

6. When Are Fees Due?

7. Broker vs M&A Advisor: Fee Differences

The terms are used inconsistently. In practice the split is deal size and sophistication: "business brokers" handle main street and small businesses ($100K–$5M); "M&A advisors" handle the lower-middle-market and above ($5M–$500M+). The cost structures differ.

• Business brokers (main street): flat 8–12%, no monthly retainer, minimum fee $10,000–$25,000, paid entirely at closing. Provide basic valuation but not sophisticated financial models. CBI (IBBA) is the recognition mark.
• M&A advisors (LMM, $5M–$50M): monthly retainer $10,000–$50,000 plus a Lehman/Modified Lehman success fee (effective ~2–5%). Prepare full Confidential Information Memoranda, financial models, buyer outreach, and manage diligence. Higher total cost for a more involved service. CM&AA or CBI typical credentials.
• Investment banks (middle market, $50M+): monthly retainer plus success fees that can reach $1M–$5M+ on a closed deal. Full institutional service with analyst teams and auction processes — beyond the scope of most individual brokers.

8. How to Negotiate the Fee (Without Losing a Good Advisor)

Fees are negotiable — but not infinitely, and not every element equally. Knowing which parts have legitimate flexibility keeps the conversation productive rather than adversarial.

9. Red Flags and Hidden Costs to Watch For

10. Fee Comparison Table — $300K to $25M

All four structures compared at key deal sizes. Figures are the success fee at close (before any retainer credit), calculated directly from each formula and matched to the live calculator above.

Read it this way: Modified Lehman produces the lowest fee at any given size, but is generally only offered on $5M+ deals — so below $5M your real choice is between flat percentage and Double Lehman, which converge near 9–10% on sub-$2M deals. Above $10M, a flat-percentage broker charging 5% costs noticeably more than an advisor on Modified Lehman. Knowing the crossover lets you ask for the structure that fits your size.

About the author

Den Unglin Founder, Solo Broker OS

I’ve spent 18+ years building, running and exiting small businesses — Solo Broker OS is that experience written down. I have an obvious stake in you choosing it, so every number on this page is sourced. Verify it yourself.