An earnout is a post-closing payment from buyer to seller that is contingent on the acquired business meeting specified financial or operational milestones after closing. Earnouts bridge valuation gaps: when buyers and sellers disagree on the target's value — typically because the seller believes in an upside the buyer cannot yet verify — an earnout lets the seller participate in that upside if it materializes. They are also among the most reliably dispute-prone provisions in any purchase agreement.

What Earnouts Are and Why They Exist

Earnouts appear most frequently in deals involving: targets with volatile or uncertain future revenue (early-stage companies, businesses in transition), acquisitions where a key person's continued involvement is critical to value, industries where regulatory approval or product launch timing affects value, and situations where market conditions have reduced buyer certainty about forward performance.

They are also used to retain sellers who will continue to manage the business post-closing — aligning the seller's incentives with post-closing performance. But this retention purpose and the dispute-avoidance purpose are often in tension, because the conditions under which the seller operates the business after closing are rarely fully specified in the acquisition agreement. That gap between what the seller expects and what the agreement actually obligates the buyer to do is where most earnout disputes are born.

How Earnouts Are Structured — The Financial Metric

The financial metric — the measure against which the earnout is tested — is the single most important structural decision. Common metrics include:

  • Revenue: Simple to measure, harder to manipulate, and generally preferred by sellers. The risk is that a buyer focused on profitability may sacrifice margins to hit a revenue target that does not reflect business health — or may divert revenue to affiliated entities outside the earnout perimeter.
  • EBITDA or Adjusted EBITDA: More aligned with value creation, but subject to disputes about what adjustments are appropriate. Buyers have substantial influence over costs allocated to the target post-closing, which can reduce reported EBITDA without reducing the underlying performance of the business.
  • Gross profit: A middle ground — captures revenue quality without exposing the seller to buyer-controlled SG&A allocations or overhead decisions that fall below the gross profit line.
  • Non-financial metrics: Product milestones, regulatory approvals, customer retention thresholds. These are unambiguous and harder for the buyer to manipulate, but they may not correlate with the value the buyer actually cares about and may become irrelevant if the business strategy shifts after closing.

The choice of metric is also a choice about who bears more risk from buyer decisions post-closing. Revenue metrics expose the seller to risk from buyer changes to pricing, sales strategy, or channel mix. EBITDA metrics expose the seller to risk from post-closing cost allocations. Non-financial metrics are less susceptible to buyer influence but may not be available or meaningful for every business.

The Measurement Period and Payment Structure

Earnout periods typically run one to three years post-closing. Longer periods increase the risk of disputes and reduce the economic present value of the earnout. Shorter periods may not capture the full performance trajectory the seller believes in and is being paid to pursue.

Earnout payments can be structured as: a single payment if the target threshold is hit at the end of the earnout period; annual payments for each year the threshold is met; or cumulative payments based on aggregate performance over the full period. Cumulative measurement reduces the risk that a single bad year eliminates the entire earnout — which sellers strongly prefer. Binary earnouts with a single annual measurement create cliff risk on both sides of the threshold.

Thresholds and caps matter. A binary earnout — pay X if threshold Y is met, nothing otherwise — is administratively simple but creates a cliff that concentrates dispute risk right at the threshold. A sliding scale with partial payments for partial performance is more forgiving, more accurately reflects value delivery, and is less likely to generate disputes over whether performance barely missed a bright-line trigger.

The Post-Closing Operating Covenant — Where Most Earnouts Break Down

The earnout agreement must specify how the target will be operated after closing. Without a strong operating covenant, the buyer can make decisions that reduce the earnout payment without breaching any express obligation. Common buyer actions that can affect earnout outcomes without explicit restriction include: changing pricing or sales strategy, diverting customers or revenue to other business units, eliminating the target's dedicated sales force, allocating additional overhead to the target, changing accounting policies that affect the earnout metric, and integrating the target with the buyer's broader operations in ways that eliminate the target's standalone financial identity.

Well-drafted earnout agreements include: an obligation on the buyer to operate the acquired business in good faith and in substantially the same manner as it was operated pre-closing; specific restrictions on intercompany asset transfers, customer reassignments, and related-party transactions during the earnout period; a prohibition on accounting or cost-allocation changes that would reduce the earnout metric; and in some cases a best efforts or commercially reasonable efforts obligation on the buyer to pursue the milestones the earnout is designed to measure.

The implied covenant of good faith and fair dealing provides some protection to sellers against buyers who deliberately undermine earnouts. But Delaware courts have been reluctant to use the implied covenant to override express contractual provisions or to second-guess legitimate post-closing business decisions. Express covenants are far more reliable than implied duties — sellers should not count on the implied covenant to do work that belongs in the agreement.

Dispute Resolution for Earnout Calculations

Earnout disputes are disproportionately common in M&A litigation. When they arise, they typically involve: disagreements about how the earnout metric is calculated (what adjustments are appropriate), whether the buyer operated the business in a manner that prevented the earnout from being earned, or whether a triggering event occurred at all.

The calculation dispute mechanism matters. Most earnout agreements provide that the buyer delivers a calculation, the seller can object within a specified window, and if the parties cannot agree, an independent accounting firm resolves the dispute. But the scope of the accounting firm's authority is critical — if the firm can only resolve accounting questions (not legal or good faith disputes), a seller who believes the buyer deliberately manipulated the underlying numbers may need to litigate the business conduct question separately from the accounting dispute, in a separate proceeding, on a different timeline.

Sellers should insist on: audit rights for the relevant financial statements during the earnout period; participation rights in key business decisions that could affect the earnout metric; and a dispute resolution mechanism that allows them to challenge both accounting calculations and buyer conduct in a single proceeding. A well-structured earnout dispute mechanism should give the seller a complete remedy — not one that requires two separate forums to resolve what is fundamentally one dispute.