M&A Advisor Engagement Letter Fee Terms

M&A advisor engagement letter fee terms decide what a seller actually pays, when it is paid, and what buyer activity can create liability after termination. Review the fee basis, cap, retainer, expenses, tail, minimum fee, transaction definition, and payment trigger before signing. Lyndon Advisory uses a simple model: 2% of enterprise value, capped at US$300,000, with no retainer or expense recharge.

The engagement letter is where fee transparency becomes enforceable. A clean proposal is useful, but the signed document controls.

Fee Terms To Review

Engagement-letter term	What to confirm	Seller risk if unclear
Success fee	Percentage and dollar examples	Percentage may not show real cost
Fee basis	Enterprise value, equity value, debt, cash, rollover, earnout	Fee may apply to value not received in cash
Fee cap	Maximum dollar fee	Larger deals become disproportionately expensive
Minimum fee	Minimum dollar payment	Smaller deals cost more than headline percentage implies
Retainer	Amount, duration, crediting	Seller pays before buyer progress
Expenses	Policy, cap, approval, receipts	Costs leak outside the fee quote
Tail provision	Covered buyers, standard of contact, duration	Seller may owe fee after termination
Payment trigger	Closing, not LOI or signing	Seller pays even if the deal fails

For a plain-English definition of the document itself, see Lyndon’s engagement letter glossary. For a full fee-market comparison, read M&A Advisory Fees.

Fee Basis Is Often The Biggest Dollar Issue

Basis	What it can include	Why sellers should care
Enterprise value	Equity value, debt, debt-like items, assumed liabilities, cash treatment	Common in M&A but must be defined precisely
Equity value	Value paid to shareholders before seller-level costs	Easier to compare to proceeds, but not always advisor standard
Transaction value	May include earnout, rollover, seller note, assumed obligations	Can create fee on deferred or contingent value

Sellers should ask for worked examples at realistic structures: cash sale, debt-free sale, rollover equity, earnout, and seller note. The fee clause should say how each component is treated.

Tail And Trigger Terms

The tail clause is the post-termination fee provision. It can be fair when it covers buyers the advisor genuinely introduced or advanced. It becomes risky when it covers broad categories, weak contacts, or stale names.

Term	Seller-friendly version
Tail buyer list	Named buyers with substantive contact during the mandate
Tail duration	Reasonable period tied to actual process timing
Success-fee trigger	Completed closing
Transaction definition	Specific sale, recapitalisation, or investment scope agreed by seller
Termination rights	Clear notice period and no open-ended economics

Axial’s 2026 M&A Fee Guide shows why this detail matters: lower-middle-market mandates can combine engagement fees, success fees, capital raising fees, and expense policies in different ways. The engagement letter is the comparison document.

The IBBA and M&A Source Market Pulse research provides additional context on lower-middle-market deal activity and seller outcomes. In a fragmented market, engagement-letter clarity is part of deal preparation, not just legal cleanup.

“An engagement letter should make the economics boring. A seller should be able to answer three questions without calling a lawyer: what is the maximum fee, what buyer activity creates a fee, and do I pay only if the transaction closes?”

— Daniel Bae, Founder & CEO, Lyndon Advisory

Lyndon Fee Terms

Term	Lyndon Advisory model
Success fee	2% of enterprise value
Cap	US$300,000
Retainer	None
Monthly fee	None
Upfront fee	None
Expense recharge	None
Trigger	Completed transaction only
Third-party providers	Engaged directly by seller when needed

Transparent terms still need institutional-quality execution. Before signing any engagement letter, confirm whether the advisor will prepare the valuation, CIM, financial model, investment story, buyer map, targeted outreach plan, confidentiality controls, negotiation strategy, and diligence plan. For the full owner process, read How to Sell a Business.

Next Step

Situation	Best next step
You are reviewing an engagement letter	Use the fee calculator
You want Lyndon’s published model	Review Lyndon fees
You want a confidential fee-fit review	Submit a valuation inquiry