M&A Advisory Fees: Complete Guide by Deal Size (July 2026)

One of the first questions business owners ask when considering a sale is: "How much will the M&A advisor cost?" It's the right question, but the answer is more nuanced than a single number. Fee structures vary based on deal size, firm type, engagement scope, and market conditions.

This guide walks through every fee component you'll encounter, with real numbers by deal size, so you can budget accurately and spot advisors who are overcharging or underdelivering.

How M&A advisory fees are structured

Most M&A advisory engagements have two fee components: a monthly retainer and a success fee paid at closing. Some firms also charge a minimum fee, an initial engagement fee, or separate expense reimbursements. Here's how each piece works.

Monthly retainer

The retainer covers the advisory team's ongoing work: financial analysis, buyer outreach, document preparation, process management, and regular communication with you. It typically ranges from $5,000 to $25,000 per month, depending on deal size and firm prestige.

Some firms credit part or all of the retainer against the final success fee. Others treat it as a separate charge. This is an important detail to clarify before signing the engagement letter.

Retainer ranges by deal size:

• $5M to $15M deals: $5,000 to $10,000 per month
• $15M to $50M deals: $10,000 to $20,000 per month
• $50M to $100M deals: $15,000 to $25,000 per month
• $100M+ deals: $20,000 to $50,000+ per month

Success fee

The success fee is the primary compensation for the advisory firm and is only paid when the deal closes. It's calculated as a percentage of the total transaction value (enterprise value, not just the equity portion). The percentage decreases as deal size increases.

Most firms base their success fee on one of three formulas:

The Lehman formula and its variations

Original Lehman formula

Created by Lehman Brothers in the 1960s, the original formula uses a tiered structure:

• 5% on the first $1 million
• 4% on the second $1 million
• 3% on the third $1 million
• 2% on the fourth $1 million
• 1% on everything above $4 million

For a $10M deal under the original Lehman formula, the success fee would be: $50,000 + $40,000 + $30,000 + $20,000 + $60,000 = $200,000 (2.0% of total value).

The original Lehman formula is rarely used today because it was designed when $10M was a large deal. With inflation, the tiers are too low to adequately compensate advisors for the work involved in modern transactions.

Double Lehman formula

The Double Lehman simply doubles each tier of the original:

• 10% on the first $1 million
• 8% on the second $1 million
• 6% on the third $1 million
• 4% on the fourth $1 million
• 2% on everything above $4 million

For the same $10M deal: $100,000 + $80,000 + $60,000 + $40,000 + $120,000 = $400,000 (4.0% of total value). This is the more common formula for lower middle market deals.

Modified Lehman formula

Many firms use a Modified Lehman that adjusts the tiers for larger deal sizes. A common version:

• 5% on the first $10 million
• 4% on the next $10 million ($10M to $20M)
• 3% on the next $30 million ($20M to $50M)
• 2% on the next $50 million ($50M to $100M)
• 1% on everything above $100 million

For a $50M deal under Modified Lehman: $500,000 + $400,000 + $900,000 = $1,800,000 (3.6% of total value). This formula is widely used in the mid-market.

M&A advisory fees by deal size

Here's what you can realistically expect to pay across different transaction sizes, including both retainer and success fee components:

These ranges assume a 12-month engagement timeline, which is typical for most deals. Faster deals will have lower total retainer costs. Longer or more complex deals may run higher.

What's included in M&A advisory fees

Understanding what you're paying for helps you evaluate whether a fee is reasonable. A full-service M&A advisory engagement typically includes:

• Business valuation and market assessment. The advisor analyzes your financials, benchmarks you against comparable transactions, and estimates your likely sale price range.
• Marketing materials. This includes a teaser (one-page blind profile sent to potential buyers), a Confidential Information Memorandum (CIM, the detailed document buyers review), and a management presentation deck.
• Buyer identification and outreach. The advisory team builds a custom list of 50 to 200+ potential acquirers and contacts each one directly. This is where the advisor's industry relationships and buyer database pay off.
• Process management. Running the bid process, managing multiple buyers simultaneously, maintaining competitive tension, and keeping the deal on track through each phase.
• Negotiation. Advising on offer terms, structuring counterproposals, and pushing for the best combination of price, structure, and certainty of close.
• Due diligence oversight. Managing the buyer's due diligence process, coordinating your team's responses, and resolving issues before they become deal-breakers.
• Closing coordination. Working with legal counsel on both sides to finalize the purchase agreement and get the deal closed.

What's usually NOT included

• Legal fees. You'll need your own M&A attorney. Budget $50,000 to $200,000+ depending on deal complexity.
• Accounting fees. Quality of earnings reports and tax structuring advice are separate costs.
• Travel expenses. Most engagement letters allow the advisor to bill reasonable travel expenses on top of the retainer.
• Transaction insurance. Reps and warranties insurance premiums are a deal cost, not an advisory fee.

Red flags in M&A fee structures

Not every fee proposal is reasonable. Watch for these warning signs when evaluating advisors:

• No retainer at all. An advisor willing to work with zero retainer on a $5M deal may sound appealing, but it usually means they'll deprioritize your deal whenever a bigger engagement comes in. A modest retainer keeps both sides committed.
• Retainer that doesn't credit against the success fee. If you're paying $15,000 per month for 12 months ($180,000) and the success fee is separate, make sure the total is justified by the deal size. For smaller deals, this can push total fees unreasonably high.
• Excessively high minimum fee. A minimum fee of $500,000 on a $5M deal (10%) is too high. Minimums should be reasonable relative to the expected deal size and workload.
• Vague scope of work. If the engagement letter doesn't specify exactly what the advisor will deliver (number of buyers contacted, marketing materials produced, process timeline), you have no way to hold them accountable.
• Long tail fees. Some agreements include "tail provisions" that entitle the advisor to a fee if you sell to any buyer they contacted, even years after the engagement ends. A 12 to 18 month tail is reasonable. A 36-month tail is not.
• No expense cap. Without a cap on reimbursable expenses, you could face unexpected charges. Ask for a cap or require pre-approval for expenses above a threshold.

How to negotiate M&A advisory fees

M&A fees are negotiable. Here are the levers you can pull:

Talk to multiple firms

Get proposals from at least three advisory firms. This gives you a clear picture of the market rate for your deal size and industry, and gives you leverage when negotiating. The best M&A advisors for mid-sized companies will respect a competitive process because they run competitive processes themselves.

Negotiate the retainer credit

Push for the retainer to be fully credited against the success fee. Many firms will agree to this, especially for attractive deals. Even a partial credit reduces your total cost significantly over a 12-month engagement.

Use tiered success fee structures

Instead of a flat percentage, propose a tiered structure that increases the advisor's fee if they exceed your price expectations. For example: 3% on the first $20M, 5% on anything above $20M. This aligns incentives and motivates the advisor to push for the highest possible price.

Cap expenses

Request a cap on reimbursable expenses, or require pre-approval for any expense above $1,000. This prevents surprise costs and keeps the advisor disciplined about spending.

Shorten the tail provision

Negotiate the tail period down to 12 months rather than 24 or 36. The tail should protect the advisor from you going around them to close a deal they originated, but it shouldn't be so long that it creates a burden if you decide to work with a different firm later.

When fees don't match value

Some situations justify paying above-market fees, and some justify pushing back hard:

Worth paying more for

• Deep industry expertise. An advisor who has closed 20+ deals in your exact industry will know exactly which buyers will pay a premium and why. That knowledge alone can be worth an extra percentage point in sale price.
• Established buyer relationships. If the advisor has done repeat transactions with the likely buyer pool, their calls get returned faster and taken more seriously. That access has real value.
• Complex deal situations. Carve-outs, cross-border transactions, or businesses with unusual structures require specialized skills. Paying a premium for that expertise prevents costly mistakes.

Not worth paying extra for

• Brand name alone. A bulge-bracket bank charging 2x the rate of a strong boutique firm for a $30M deal isn't giving you 2x the outcome. For lower middle market deals, boutique firms often outperform larger banks because your deal gets their senior team's full attention.
• Promises without track record. An advisor promising a premium valuation without comparable deal experience is selling, not advising. Ask for references from sellers with businesses similar to yours.

Checklist for evaluating M&A fee proposals

• Get proposals from at least 3 advisory firms before committing
• Confirm whether the retainer credits against the success fee
• Verify the success fee formula and calculate the actual dollar amount at your expected deal size (our M&A fee calculator models Lehman, Double Lehman, and modern market fees side by side)
• Check for minimum fee provisions and make sure they're reasonable
• Review the tail provision length (12 months is standard, 24+ is aggressive)
• Ask about expense reimbursement policies and request a cap
• Confirm what's included in the scope of work (buyer list size, materials, timeline)
• Request references from sellers in your industry and deal size range
• Review the termination clause and make sure you can exit if performance doesn't meet expectations
• Ask about the specific deal team members who will work on your transaction

M&A advisory fees for SaaS and software companies

SaaS and software deals carry their own fee dynamics that differ from traditional lower middle market transactions. Advisors who specialize in software M&A structure their engagements around ARR multiples and growth rates rather than EBITDA multiples — which changes how they size retainers, frame success fees, and position the deal.

How SaaS deal complexity affects your fee structure

Software companies with recurring revenue involve extra diligence work: revenue recognition under ASC 606, customer concentration analysis, net revenue retention benchmarks, and VSOE (vendor-specific objective evidence) documentation. Advisors who know this space build that complexity into their engagements upfront, which typically means slightly higher retainers but faster processes because they aren't learning your business model mid-deal.

For SaaS deals in the $3M–$30M ARR range, here's what you should expect:

• Monthly retainer: $8,000–$20,000/month, credited against the success fee at close. Advisors handling software deals at the lower end (under $5M ARR) often price closer to $8,000–$12,000; those running competitive processes for $15M+ ARR businesses typically charge $15,000–$20,000.
• Success fee: 4%–7% of enterprise value for sub-$20M ARR SaaS businesses, dropping to 2.5%–4% for deals above $30M ARR. Many advisors use a minimum fee of $200,000–$350,000 on software transactions.
• ARR vs. EBITDA framing: Software buyers value recurring revenue, not earnings. A business running at breakeven with $5M ARR may sell at 4–6x ARR rather than an EBITDA multiple. Your advisor should be pitching ARR multiples and net dollar retention — not trying to explain away low EBITDA.

What SaaS founders actually pay (and what they negotiate)

The most commonly negotiated points in software M&A engagements are the retainer credit structure (whether 100% of paid retainer offsets the success fee or only a portion), the tail provision scope (which buyer contacts count if you close post-engagement), and the minimum fee floor. SaaS deals often attract a wider buyer pool than traditional businesses — PE firms, strategics, and growth-stage acquirers all compete — which means a structured process adds more relative value. Don't negotiate the success fee percentage down; negotiate the retainer amount, the credit terms, and the expense cap instead.

For a software business with $4M ARR and 80% gross margins selling at a 5x multiple ($20M enterprise value), a typical advisor fee at 5% success fee less credited retainer runs $700,000–$900,000 total. That's a real cost — but advisors who run competitive software processes routinely deliver 30%–50% higher exit multiples than founders achieve in direct negotiations. The net return on a good advisor is almost always positive.

Current trends in M&A advisory fees (July 2026)

Fee structures in the lower middle market have shifted noticeably through the first half of 2026. Deal volume is tracking ahead of 2025's record pace, which means buyers are competing harder — and sellers with quality businesses have more negotiating leverage on fee structures than they have in years.

What we're seeing in the market as of July 2026:

• Retainer compression on smaller deals — For transactions below $10M, competition among boutique advisory firms has pushed monthly retainers toward the lower end of the range ($5,000–$8,000/month), while senior-team access and process quality have held or improved.
• Success fee floors are holding at 4–5% for LMM — Despite increased competition, most reputable lower middle market firms aren't discounting their success fee percentages. The negotiation happens on retainer credits and minimum fee thresholds, not on the percentage itself.
• Performance-based structures gaining ground — A growing number of advisors now offer hybrid models that tie a portion of the success fee to specific outcomes, such as achieving a price above a target floor. This aligns incentives and gives sellers more confidence that the advisor is working toward the best outcome, not just the fastest close.
• AI-driven buyer matching is reducing process timelines — Several top advisory firms have integrated AI-powered proprietary buyer databases, which can compress the buyer outreach phase from 8–12 weeks to 4–6 weeks. Faster timelines mean lower total retainer costs even at the same monthly rate.
• Quality of Earnings costs are rising — Buyers are requiring more rigorous QoE reports than they were two years ago, particularly on deals above $15M. Budget an additional $15,000–$40,000 for third-party QoE preparation on mid-market transactions.
• Sector specialists continue to command premiums — Advisors with documented deal experience in SaaS, healthcare, and tech-enabled services are commanding 0.5–1.0 percentage points above generalist market rates, and are consistently delivering better buyer pools to justify it.

Understanding these dynamics helps you negotiate more effectively and spot advisors who are using outdated fee structures. For additional benchmarks, the Association for Corporate Growth (ACG) publishes annual research on middle market deal activity and advisory fee norms. For business owners in New York specifically, see our rankings of the best M&A advisory firms in New York City. If you're comparing advisor options by firm tier, our ranking of top LMM M&A advisory firms covers performance data across 68 tracked firms.