How to Structure an Earn‑out in UK M&A (2026): EBITDA vs Revenue, Caps, Clawbacks, Security and Leakage Controls

Understanding how to structure an earn out in UK M&A has become an essential competency for deal teams navigating the persistent valuation gaps that define the 2026 transaction landscape. Higher debt costs, tighter sponsor scrutiny and cautious lender appetite mean that earn‑outs are no longer a secondary pricing mechanism, industry observers note they are now a standard feature of mid‑market and PE‑backed transactions across the United Kingdom. This practical playbook covers every structural lever, from choosing between EBITDA and revenue metrics to drafting enforceable caps, clawbacks, security packages and leakage controls, so that buyers, sellers, lenders and their advisers can negotiate earn‑out arrangements that genuinely bridge price expectations without creating post‑completion disputes.

What Is an Earn‑Out? Definitions and Common Forms

An earn‑out is a contractual mechanism within a share purchase agreement (SPA) or asset purchase agreement under which part of the purchase price is contingent on the target business achieving specified performance thresholds after completion. In accounting terms, earn‑outs represent contingent consideration, a component of the acquisition price that depends on uncertain future events.

The earn‑out meaning in M&A is straightforward: the seller accepts a lower upfront payment in exchange for the opportunity to receive additional consideration if the business meets agreed targets. In private equity, earn‑outs serve a dual purpose, they align the seller’s post‑completion incentives with the sponsor’s value‑creation thesis while transferring forecast risk away from the buyer.

Earn‑out arrangements typically fall into three structural categories:

When to Use Earn‑Outs, Commercial and Deal Triggers

Earn‑outs are not appropriate for every transaction. They introduce complexity, create ongoing relationships between buyer and seller, and carry significant dispute risk. The decision to include one should be driven by specific commercial triggers.

• Valuation gap. The buyer and seller disagree on enterprise value, often because the seller’s financial projections are aggressive or unproven.
• Key‑person dependency. The target’s value is concentrated in the founder or a small management team whose retention is essential.
• Immature revenue streams. New products, recent market entry, or early‑stage customer pipelines make future performance genuinely uncertain.
• Regulatory or milestone risk. Approval, licensing or contract renewals that will materially affect value are pending at completion.

Earn‑Outs and Failure Points, a Practical Risk Checklist

Research consistently identifies integration failure and misaligned incentives as leading causes of M&A underperformance. When an earn‑out is poorly drafted, it amplifies these risks: the seller may resist operational changes needed for integration, while the buyer may be tempted to suppress earn‑out metrics through cost allocation or revenue re‑routing. Industry observers expect this tension to intensify in 2026 as sponsors pursue faster integration timelines. Before agreeing to an earn‑out arrangement, both parties should assess whether the metric can be cleanly isolated from integration effects and whether the governance framework is robust enough to survive 12 to 36 months of shared oversight.

How to Structure an Earn‑Out in UK M&A: The Seven Structural Elements

Every earn‑out in a UK transaction is built from seven interdependent elements. Negotiating each one in isolation creates inconsistencies; they should be addressed as a single package within the SPA.

1. Headline Price Allocation

Decide the total enterprise value and the split between upfront consideration and contingent consideration. In current UK mid‑market practice, the upfront element typically represents 60–80% of the headline price, with the earn‑out accounting for the balance.

2. Upfront Percentage vs Contingent Percentage

A higher upfront percentage reduces seller risk and strengthens the seller’s negotiating position on other SPA protections. A lower upfront percentage gives the buyer greater downside protection but may require the buyer to offer more generous earn‑out mechanics (wider caps, security, shorter measurement periods) to make the deal acceptable.

3. Earn‑Out Period

Most UK earn‑outs run for 12 to 36 months post‑completion. Shorter periods suit transactions where the key milestone is near‑term (a contract renewal or product launch); longer periods are appropriate for businesses where growth trends need time to materialise. Periods beyond 36 months are uncommon because they create fatigue, increase dispute probability and complicate lender consent.

4. Performance Metrics

The choice of metric, EBITDA, revenue, gross profit, ARR or a non‑financial KPI, is the single most consequential structural decision. This is explored in detail below.

5. Measurement and Calculation

Define the accounting policies to be used for measurement (typically consistent with the target’s historical policies), specify who prepares the earn‑out accounts, set the timetable for delivery of draft and final accounts, and prescribe the dispute resolution mechanism for disagreements. The ICAEW’s Earn‑Out Agreements guideline recommends that the SPA include a detailed schedule of agreed accounting policies to reduce ambiguity.

6. Payment Mechanics

Specify the currency, form of payment (cash, loan notes, shares), timing (lump sum or instalments), and any escrow or holdback arrangements. Where debt is involved, confirm that the payment waterfall does not conflict with the lender’s intercreditor position.

7. Governance and Enforcement

Operational covenants govern how the buyer must run the target business during the earn‑out period. Common provisions include restrictions on material changes to business strategy, requirements to maintain adequate working capital, obligations to provide the seller with financial information, and rights for the seller to access premises and records.

Worked example (£ deal): A PE sponsor acquires a UK software business for a headline price of £20 million. The SPA allocates £14 million (70%) as upfront cash consideration and up to £6 million (30%) as earn‑out consideration, payable in two annual tranches over a 24‑month period, contingent on the target achieving specified annual recurring revenue targets.

EBITDA vs Revenue and Other Earn‑Out Metrics: Pros, Cons and Worked Examples

Choosing the right performance metric is the most debated element when structuring an earn‑out in the UK. The table below summarises how buyers and sellers typically view the three most common options.

When EBITDA Works, and When It Does Not

EBITDA is the dominant metric in PE‑backed UK transactions because it aligns earn‑out payments with the cashflow that underpins the buyer’s investment thesis. However, EBITDA is a non‑GAAP measure, and its calculation requires meticulous definition within the SPA. Buyers and sellers must agree on the treatment of management charges, intercompany allocations, exceptional items, share‑based payment costs, and any add‑backs. Where the buyer plans significant post‑completion restructuring, relocating staff, consolidating premises, centralising procurement, EBITDA-based earn‑outs become contentious because the seller will argue that buyer‑driven cost increases suppress the metric artificially.

Revenue: Clarity with Caveats

Revenue‑based earn‑outs offer measurement simplicity: top‑line figures are typically audited and harder to manipulate through cost allocation. The trade‑off is that revenue rewards growth regardless of profitability. A seller could theoretically inflate revenue through aggressive discounting, extended payment terms or channel stuffing. Buyers should consider whether revenue recognition policies need to be locked in the SPA and whether returns, credits and rebates must be netted off.

Non‑Financial KPIs

For technology, pharmaceutical and service businesses, non‑financial KPIs, customer retention rates, regulatory approvals, product development milestones, can supplement or replace financial metrics. These are useful when the primary value driver is not yet reflected in the P&L. The drafting challenge is objectivity: KPIs must be defined with enough precision to be independently verifiable.

Worked Example A, EBITDA‑Based Earn‑Out

Headline price: £15 million. Upfront: £10 million. Earn‑out: up to £5 million over 24 months. Target: adjusted EBITDA of £3 million in Year 1. Payout: if adjusted EBITDA reaches £3 million, £2.5 million is payable; if it reaches £3.5 million, the full £5 million is payable (linear interpolation between thresholds). If EBITDA falls below £2.5 million, nothing is payable (floor).

Worked Example B, Revenue‑Based Earn‑Out

Headline price: £8 million. Upfront: £5.5 million. Earn‑out: up to £2.5 million over 12 months. Target: net revenue of £10 million. Payout: £1 of earn‑out for every £1 of net revenue above £8 million, capped at £2.5 million. Revenue below £8 million triggers no payment.

Caps, Collars, Floors and Payment Curves in UK Earn‑Out Structures

Market practice in UK M&A requires every earn‑out to include upper and lower boundaries. Without these, the buyer faces uncapped liability and the seller faces unlimited downside. The following norms are commonly observed in current deal practice.

• Cap. The maximum earn‑out payment, typically expressed as a percentage of the headline price. In UK mid‑market deals, caps commonly range from 20% to 40% of total consideration.
• Floor. The minimum performance level below which no earn‑out is payable. This protects the buyer from paying for underperformance.
• Collar. A band within which payments scale linearly (pro‑rata), with no payment below the floor and full payment at the cap.
• Step / tiered curves. Payments increase in discrete steps at pre‑defined performance bands rather than on a continuous basis.

Sample clause (illustrative only): “The Contingent Consideration shall be calculated as follows: (a) if Adjusted EBITDA for the Earn‑Out Period is less than £2,500,000, no Contingent Consideration shall be payable; (b) if Adjusted EBITDA equals or exceeds £2,500,000 but is less than £3,500,000, the Contingent Consideration shall equal (Adjusted EBITDA minus £2,500,000) multiplied by 2.5; (c) if Adjusted EBITDA equals or exceeds £3,500,000, the Contingent Consideration shall be £2,500,000 (the Cap).”

Clawbacks, Acceleration Events and Seller Protections

Earn‑out disputes frequently arise when post‑completion events disrupt the measurement period. Both parties need contractual mechanisms to address this risk.

• Clawback provisions. Allow the buyer to recover earn‑out payments already made if it subsequently emerges that the earn‑out accounts were prepared on an incorrect basis or that the seller committed fraud or breached material warranties. Clawback rights typically survive for 12 to 24 months after the final earn‑out payment.
• Acceleration triggers. Entitle the seller to receive the full (or an agreed proportion of the) earn‑out immediately if the buyer takes actions that materially impair the target’s ability to achieve the performance thresholds, for example, selling the business, stripping material assets, or terminating key contracts without the seller’s consent.
• Set‑off restrictions. Sellers commonly negotiate limits on the buyer’s ability to set off warranty or indemnity claims against earn‑out payments, ensuring that disputed amounts are ringfenced pending resolution.

Sample acceleration clause (illustrative only): “If at any time during the Earn‑Out Period the Buyer disposes of all or substantially all of the assets of the Target, the Contingent Consideration shall be deemed to have been earned in full and shall become immediately payable.”

Security, Escrow, Guarantees and Lender / Intercreditor Mechanics

An earn‑out is only as valuable as the buyer’s ability to pay when the obligation crystallises. In leveraged transactions, this requires careful coordination with lenders.

Security Options for Sellers

• Escrow accounts. A portion of the upfront consideration or a separate deposit is held in escrow by a third‑party agent, released to the seller upon achievement of earn‑out targets. Escrow amounts in UK mid‑market deals typically range from 10% to 25% of the contingent element.
• Holdback / retention. The buyer retains part of the upfront consideration as security, releasing it in tranches as earn‑out obligations are settled.
• Parent company guarantee. The buyer’s parent or sponsor provides a corporate guarantee for the earn‑out obligations.
• Security over assets. Less common but available: the seller takes a second‑ranking charge over the target’s assets or shares, subordinated to the senior lender.

Lender and Intercreditor Considerations

Where the acquisition is debt‑financed, the senior lender will scrutinise earn‑out mechanics closely. Lenders commonly require that earn‑out payments are subordinated to senior debt service, that the buyer obtains lender consent before making earn‑out payments above a de minimis threshold, and that earn‑out obligations are included in the debt waterfall and financial covenant calculations. The intercreditor agreement should expressly address the ranking of earn‑out claims relative to senior and mezzanine debt, and any restrictions on the seller’s ability to enforce earn‑out rights (including standstill periods and enforcement moratoria).

Leakage, Covenant Controls and Buyer Operational Freedom

Leakage in the earn‑out context refers to actions by the buyer that extract value from the target during the earn‑out period, artificially suppressing the performance metric and reducing the seller’s payout.

• Prohibited leakage. Management fees charged by the buyer or its affiliates, intercompany transactions at non‑arm’s length prices, dividends or distributions to the buyer, and any asset transfers to group companies without fair value consideration.
• Permitted leakage. Pre‑agreed items such as normal‑course salary payments, tax payments, and expenditures in the approved budget.

Sample anti‑leakage covenant (illustrative only): “During the Earn‑Out Period, the Buyer shall not, and shall procure that the Target shall not, without the prior written consent of the Seller: (a) declare or pay any dividend or distribution; (b) enter into any transaction with any member of the Buyer’s Group otherwise than on arm’s length terms; (c) make any material change to the accounting policies of the Target.”

Buyers will push back on overly restrictive covenants that prevent legitimate integration. The practical compromise typically involves a detailed schedule of permitted actions annexed to the SPA, coupled with a materiality threshold below which buyer actions are unconstrained.

Accounting and Tax: IFRS 3, Contingent Consideration and UK Tax Checks

The earn‑out accounting treatment under IFRS demands careful attention from finance teams on both sides of the transaction.

IFRS 3, Contingent Consideration

Under IFRS 3 Business Combinations, contingent consideration (including earn‑outs) must be recognised at fair value at the acquisition date and classified as either a financial liability or equity. In most UK earn‑out arrangements, the obligation is classified as a financial liability because the buyer is required to deliver cash. Subsequent changes in fair value are recognised in profit or loss, not as adjustments to goodwill, which means that earn‑out remeasurements directly affect the buyer’s reported earnings in each subsequent period.

UK Tax Considerations

For sellers, earn‑out receipts are generally subject to capital gains tax (CGT) where the consideration relates to the disposal of shares. HMRC guidance distinguishes between earn‑out payments that are genuine purchase consideration (taxed as capital) and payments that are disguised employment income (taxed as income under the employment‑related securities rules). Where the seller remains employed by the target post‑completion and the earn‑out is linked to personal performance rather than business performance, HMRC may re‑characterise part or all of the earn‑out as employment income.

Sellers and their advisers should ensure that the earn‑out is structured to meet the conditions for capital treatment, principally that the earn‑out is linked to business‑level metrics, is available to all shareholders proportionally, and is not conditional on continued employment.

Finance Team Reporting Checklist

• Obtain a fair value assessment of contingent consideration at acquisition date (typically from an independent valuer).
• Document the classification rationale (liability vs equity) under IFRS 3.
• Establish a remeasurement schedule aligned with the earn‑out payment dates.
• Confirm CGT vs income tax treatment with tax advisers before completion.
• Ensure earn‑out payment obligations are disclosed in the notes to the financial statements.

Dispute Resolution, Measurement Panels and Forensic Audit Rights

Earn‑out disputes are among the most common sources of post‑completion litigation in UK M&A. A well‑drafted SPA anticipates this by including a structured dispute resolution mechanism.

• Draft earn‑out accounts. The buyer (or the target’s management) prepares draft earn‑out accounts within 60 to 90 days of the end of each measurement period.
• Seller review period. The seller has 30 to 45 days to review and raise objections.
• Negotiation period. The parties attempt to resolve disputes within a further 15 to 30 days.
• Independent accountant determination. Unresolved items are referred to an independent firm of chartered accountants (commonly one of the Big Four or a specialist forensic accounting firm), acting as expert and not as arbitrator. The determination is final and binding, save in the case of manifest error.
• Forensic audit rights. The seller should negotiate contractual rights to access the target’s books, records, systems and premises during the earn‑out period, and to appoint its own accountant to review the earn‑out accounts.

Examples of Earn‑Out Structures: Worked Templates

Template 1, EBITDA Earn‑Out (PE‑Backed Acquisition)

Deal: PE fund acquires a UK manufacturing business. Headline price: £25 million. Upfront: £17.5 million (70%). Earn‑out: up to £7.5 million over 24 months (two annual measurement periods). Metric: adjusted EBITDA. Year 1 target: £4 million adjusted EBITDA → £3 million payable. Year 2 target: £5 million adjusted EBITDA → £4.5 million payable. Floor: £3 million adjusted EBITDA (below which nothing is payable in that year). Cap: £7.5 million aggregate. Security: £2 million held in escrow; parent guarantee for the balance.

Template 2, Revenue Earn‑Out (Technology Acquisition)

Deal: Strategic acquirer purchases a UK SaaS company. Headline price: £12 million. Upfront: £8 million (67%). Earn‑out: up to £4 million over 12 months. Metric: net recurring revenue. Payout: £1 for every £1 of net recurring revenue above £6 million, capped at £4 million. Floor: £6 million (no payment below). Security: holdback of £1 million from upfront consideration; remainder unsecured with parent guarantee.

Conclusion: Key Negotiation Priorities for Structuring UK Earn‑Outs in 2026

Knowing how to structure an earn out in UK M&A requires balancing commercial ambition against contractual precision. The 2026 deal environment, characterised by valuation uncertainty, sponsor caution and lender assertiveness, makes disciplined earn‑out structuring more important than ever. Each party should approach the negotiation with clear priorities.

• Buyers should focus on metric controllability, clear accounting policy schedules, robust anti‑leakage protections, and lender consent alignment.
• Sellers should prioritise security (escrow or guarantee), acceleration protections, independent measurement rights, and restrictions on the buyer’s ability to set off claims against earn‑out payments.
• Lenders should ensure that earn‑out obligations are subordinated, included in covenant calculations, and subject to consent and standstill provisions in the intercreditor agreement.

Earn‑outs remain one of the most effective tools for bridging valuation gaps in UK M&A transactions, but only when they are drafted with the specificity and foresight that a contested post‑completion environment demands. Deal teams should engage specialist M&A counsel early in the process and consider the full range of structural levers outlined in this guide. For access to experienced M&A lawyers in the United Kingdom, explore the Global Law Experts directory.

Sources

1. Practical Law (Thomson Reuters), Negotiating Earn‑outs Chart
2. TLT LLP, M&A Fundamentals: Earn‑outs in M&A Transactions
3. ICAEW, Earn‑Out Agreements Guideline (2023)
4. Grant Thornton, Earn‑outs: How to Avoid Pitfalls and Protect Value
5. Slaughter and May, Key Tips and Traps for Earn‑outs in International M&A
6. HM Revenue & Customs (HMRC), Official Guidance
7. IFRS Foundation, IFRS 3 Business Combinations