An earn-out can bridge a valuation gap in a startup acquisition, or turn the sale price into a dispute; this 2026 guide shows founders how to draft the mechanism before signing.
- An earn-out clause in a 2026 startup acquisition needs a formula, reporting duty, audit right and payment date.
- ARR, revenue and EBITDA are not interchangeable metrics; define the accounting rules before signing the SPA.
- A 12-to-24-month earn-out is easier to administer than an open-ended promise tied to future growth.
- Founders should retain operating protection after closing; without it, the buyer can control the result and deny the payment.
Why an earn-out matters in a startup acquisition
An earn-out defers part of the purchase price and makes payment conditional on post-closing performance. It is common when the seller and buyer disagree about the value of a product, customer base, recurring revenue or founder-led commercial pipeline. In 2026, the clause belongs in the acquisition model and the share purchase agreement, not in an informal side letter.
The first internal reference to review is the share purchase agreement guide for M&A transactions, because the earn-out must fit the SPA’s conditions precedent, warranties, closing mechanics and dispute process. A clause that works in a spreadsheet but conflicts with the rest of the SPA will not protect either side.
An earn-out also changes the founder’s role after closing. The buyer may own the company, appoint the management team and control budgets while the founder remains dependent on decisions that affect the earn-out calculation. The drafting question is therefore not only what target to hit. It is who controls the path to that target.
Who this guide is for
This guide is for founders selling a French or European startup through a share acquisition, a strategic buyer acquiring the company, and investors negotiating a secondary exit where part of the price depends on future performance. It is also useful for a founder who will remain as an employee, executive or adviser after closing.
It is not a valuation model and it does not replace tax advice. Use it to identify the contractual terms that must be quantified before the buyer’s first draft arrives. The stronger the term sheet or letter of intent, the fewer economic surprises remain for the definitive SPA.
What to look for in an earn-out clause
1. A metric that can be calculated without interpretation
Revenue, annual recurring revenue, gross margin, EBITDA, bookings and customer retention produce different incentives. A founder should not accept the phrase commercial performance without a definition. State the metric, the accounting period, the currency, the treatment of acquisitions and the person responsible for certification.
For a SaaS business, ARR can be a useful metric only when the contract explains upgrades, downgrades, churn, unpaid invoices, multi-year contracts and foreign-exchange conversion. For a marketplace, gross transaction value is not the same as net revenue. For a services business, signed orders are not the same as collected cash.
2. A time window with a fixed payment date
A 12-to-24-month period is easier to operate than an earn-out with no end date. The SPA should state the start date, the measurement dates, the deadline for delivering the calculation and the payment date. If the seller will receive instalments, state whether each instalment is independent or whether a shortfall in one period can be recovered later.
The 2026 drafting test is simple: a finance lead who did not negotiate the deal should be able to identify the target period in under 2 minutes. If the date depends on a later board decision, the clause is unfinished.
3. Operating covenants after closing
The buyer needs freedom to run the acquired company, but the seller needs protection against deliberate action that makes the earn-out impossible. The SPA can require the buyer to operate the business in good faith, maintain reasonable resources, avoid diverting revenue and preserve agreed customer relationships.
Do not promise the founder a fixed budget unless the buyer will actually accept that restriction. Instead, list the decisions that materially affect the metric: moving contracts to another group entity, changing revenue recognition, discontinuing a product, combining sales teams or cancelling a customer contract for group-wide reasons.
4. Information and audit rights
A seller cannot verify an earn-out from a payment notice alone. Require periodic reporting, access to relevant books and records, a right to ask reasonable questions and an independent expert process for a calculation dispute. Set a notice period for objections, such as 20 business days, and explain what happens if the seller does not object in time.
The audit right should cover data necessary to test the metric without giving the seller unlimited access to unrelated confidential information. A neutral accountant can inspect the records and issue a determination. The contract should say whether that determination is final, binding or open to challenge for manifest error.
5. Treatment of extraordinary events
The metric can be distorted by a merger, a major restructuring, a group reorganisation, a change in pricing, a cyber incident or a customer moving from one group entity to another. The clause should explain whether the target is adjusted, suspended or measured on a like-for-like basis.
This matters when the startup is acquired by a larger group. A target based on standalone ARR becomes difficult to test if contracts are migrated into the buyer’s billing system. Define the data source before closing, and preserve a reconciliation between the acquired company’s figures and the buyer’s consolidated figures.
6. Employment, departure and acceleration
Many earn-outs depend on the founder remaining employed. That condition must distinguish voluntary resignation, dismissal without serious misconduct, incapacity, death, a material breach by the buyer and a change in role. A founder who is removed without cause should not automatically lose an earned payment.
Consider a protection for a change of control during the earn-out period. If the buyer resells the company after 6 months, the seller needs to know whether the earn-out accelerates, transfers to the new buyer or is replaced by a cash settlement. The answer belongs in the SPA, not in an expectation about the buyer’s future intentions.
Earn-out structures to compare before signing
Fixed milestone with a binary payment — the cleanest structure
The buyer pays a defined amount if one objective milestone is met by a fixed date. The milestone could be a signed customer contract, a regulatory approval or a product launch. The mechanism is easy to calculate, but the seller can lose the entire amount if the target is narrowly missed. Verdict: Consider when the milestone is outside the buyer’s sole control and the amount is limited.
Graduated performance scale — the balanced structure
The payment increases across defined bands, for example a lower payment at 80% of target, a mid-point payment at 100% and a capped maximum at 120%. The bands should be written as a formula, not left to negotiation after the period ends. This structure reduces the cliff effect and gives both sides a reason to keep measuring accurately. Verdict: Buy for a revenue or ARR earn-out with reliable monthly reporting.
Multiple metrics with a weighted score — the precision structure
A weighted model can combine revenue, gross margin and customer retention. It prevents the founder from hitting revenue by accepting uneconomic contracts, but it creates more opportunities for disagreement. Each metric needs its own definition, weight, data source and anti-manipulation rule. Verdict: Consider when one metric would invite harmful behaviour and the buyer will provide transparent reporting.
Founder-controlled commercial target — the founder-dependent structure
This model ties payment to sales, partnerships or customer retention that depend heavily on the founder. It can reflect the real value of the founder’s relationships, but it also creates employment and management tension. The buyer must define the founder’s authority, budget, team and access to customers. Verdict: Consider only with clear role protection and a no-fault departure rule.
Open-ended promise tied to future growth — the unsafe structure
An earn-out described as a share of future success without a measurement period, accounting rules or payment timetable is not a usable clause. It leaves the most important terms for later, when the buyer controls the business and the seller has less bargaining power. Verdict: Skip in a 2026 acquisition.
What to avoid
- A target defined by a spreadsheet only. Attach the formula or reproduce it in the SPA so the legal obligation does not depend on a file that can be replaced.
- A metric the buyer can move between entities. Add rules for group sales, transferred customers, bundled pricing and internal recharges.
- Automatic forfeiture after any departure. Separate a voluntary bad-leaver departure from a buyer-led termination without cause.
- No remedy for delayed information. Add a reporting deadline, interest on late payment where appropriate and a dispute path.
- An earn-out that silently replaces the fixed price. State the cash due at closing, the deferred amount and the maximum contingent amount separately.
Comparison table
| Structure | Best use | Main risk | Verdict 2026 |
|---|---|---|---|
| Binary milestone | Approval or defined launch | All-or-nothing result | Consider |
| Graduated scale | Revenue or ARR | Formula complexity | Buy |
| Weighted metrics | Quality plus growth | Data disputes | Consider |
| Founder-dependent target | Relationship-led sales | Role and departure conflict | Consider |
| Open-ended promise | None | No enforceable calculation | Skip |
How the earn-out fits the rest of the deal
Letter of intent
Set the economic headline in the letter of intent: the amount paid at closing, the contingent amount, the period, the target family and the principle that the buyer will not deliberately frustrate payment. The 2026 M&A letter of intent guide covers the binding and non-binding sections that should be kept distinct.
Warranty package and disclosure
An earn-out does not replace disclosure. The seller still needs to identify known customer, tax, employment, intellectual-property and data risks. The asset and liability warranty guide for startup sales is useful because warranty claims and earn-out disputes can overlap, but they are different mechanisms with different proof requirements.
Seller’s continuing role
If the founder stays, use a separate employment or consultancy document for role, pay, authority and termination. Do not hide employment terms inside the earn-out formula. The SPA should cross-reference the documents and say which event affects the deferred price.
Closing and payment security
The deferred price is still part of the negotiated consideration. Ask whether it is unsecured, held in escrow, supported by a guarantee or protected by a parent undertaking. A high headline price with an unsecured earn-out controlled entirely by the buyer is not equivalent to cash at closing.
FAQ
What is an earn-out clause in a startup acquisition?
An earn-out clause defers part of the acquisition price and makes payment conditional on defined post-closing results. The SPA should specify the metric, period, formula, reporting and dispute process.
How long should a startup earn-out last in 2026?
A 12-to-24-month earn-out is usually easier to administer than an open-ended period. The right term depends on the sales cycle, integration plan and metric, but the payment dates must be fixed before signing.
Which earn-out metric is best for a SaaS startup?
ARR can work for a SaaS startup when the SPA defines churn, upgrades, downgrades, discounts, unpaid invoices and transferred contracts. Revenue or gross margin may be better when billing practices are changing.
Can a buyer control the earn-out result?
Yes, the buyer often controls budgets, staffing and customer decisions after closing, which is why operating covenants and information rights matter. The clause should address deliberate diversion, material changes and group reorganisations.
Does a founder lose the earn-out after leaving the company?
Not automatically. The SPA should distinguish voluntary departure, misconduct, dismissal without cause, incapacity and buyer breach, then state the effect on earned and unearned amounts.
Should an earn-out be included in the letter of intent?
Yes, the letter of intent should record the headline amount, period and metric family even if the detailed formula remains non-binding. Leaving the economic principle open until the SPA invites a late dispute.
How is an earn-out dispute resolved?
The SPA should provide a calculation notice, an objection window and an independent expert process with a defined scope. It should also state whether the expert’s decision is final except for manifest error.
One last thing
The most valuable earn-out protection is often not a higher percentage. It is a rule preventing the buyer from moving the relevant customer, invoice or revenue into another group entity to change the calculation. Test the clause against a customer transfer on day 90, a founder dismissal on day 180 and a resale on day 270 before signing in 2026.
Related guides
Lina provides fixed-fee corporate and M&A legal services for European startup founders and businesses. Have the full acquisition documents reviewed before signing.