A "best efforts" clause within an earnout provision imposes a stringent obligation on the buyer. It is generally understood to be the highest standard of commitment, requiring more than just a good faith or reasonable attempt.

While the precise definition can be ambiguous and vary by jurisdiction, courts often interpret "best efforts" to mean that the buyer must take all reasonable and diligent actions to maximize the potential for the earnout to be paid.

This does not typically require the buyer to act against its own significant business interests or incur substantial, unforeseen costs. However, it does imply a proactive and dedicated approach.

For example, a buyer under a "best efforts" obligation may be expected to adequately fund the acquired business, dedicate sufficient managerial resources, and not take actions that would knowingly hinder the achievement of the earnout targets.

While often viewed as a step below the more stringent "best efforts" standard, its precise meaning can be ambiguous and is a frequent point of negotiation and, at times, litigation.

Generally, a "reasonable best efforts" clause obligates the buyer to take diligent and commercially reasonable actions to help the acquired business meet its performance goals.

Unlike the more demanding "best efforts," this standard explicitly allows the buyer to balance its obligations to the seller with its own economic interests and operational considerations. The buyer is not typically required to take actions that would be financially detrimental or significantly disrupt its existing business.

However, "reasonable best efforts" is not a passive commitment. It requires more than just good faith and prohibits the buyer from intentionally or negligently hindering the earnout's achievement.

For example, a buyer would likely be expected to provide adequate resources and not divert opportunities from the acquired business.

In M&A earnout provisions, "reasonable efforts" is another common standard of conduct imposed on the buyer. It is generally considered less demanding than "best efforts" and is often viewed as being at the lower end of the "efforts" clauses hierarchy.

While legal interpretations can vary, this standard typically requires a party to act in a commercially reasonable manner to achieve the earnout targets.

A "reasonable efforts" clause means the buyer must take some diligent action, but it allows for a significant degree of discretion. The buyer can heavily weigh its own costs, benefits, and commercial interests against the seller's interest in receiving the earnout payment.

A buyer under this standard is not expected to incur substantial or unreasonable expenses, take actions that could harm its own business, or fundamentally alter its post-acquisition plans to help the seller achieve the earnout.

Essentially, the buyer must not act in bad faith or intentionally sabotage the earnout's potential, but it is not obligated to go to great lengths or make significant sacrifices. Because the term is inherently vague and affords the buyer considerable latitude, sellers often negotiate for more specific, objective covenants instead of relying solely on a "reasonable efforts" standard.

In an M&A earnout, a "commercially reasonable efforts" clause sets a standard of conduct for the buyer that is explicitly tied to business and economic practicalities. It is often seen as synonymous with "reasonable efforts" as this standard obligates the buyer to take steps to achieve the earnout targets that a sensible business person would take in similar circumstances.

The key feature of "commercially reasonable efforts" is the explicit permission for the buyer to consider its own economic interests, including costs, profitability, and potential risks. The buyer is not required to spend unreasonable sums of money, sacrifice its own more profitable opportunities, or act in a way that is detrimental to its overall business strategy simply to help the seller achieve the earnout. The focus is on prudent, sensible business conduct rather than exhaustive or heroic measures.

While this standard gives the buyer significant discretion, it does not permit complete inaction or bad faith. The buyer must still operate the acquired business in a manner consistent with reasonable commercial practices. Because of the emphasis on the buyer's own financial well-being, sellers often seek to bolster this clause with specific, objective covenants to ensure meaningful actions are taken to support the earnout's success.

A "good faith efforts" clause generally represents the lowest affirmative standard of conduct for the buyer. In many jurisdictions, an obligation to act in good faith is already implied in all contracts, meaning this clause may not add substantial duties beyond what the law already requires.

A "good faith" standard primarily focuses on the buyer's subjective intent. It obligates the buyer to act with honesty and fairness, and most importantly, not to act in a manner specifically intended to prevent the seller from achieving the earnout milestones.

This means the buyer cannot deliberately sabotage the business, divert revenue, or otherwise actively work against the earnout's success.

However, "good faith efforts" does not typically require the buyer to take any specific, proactive steps to help achieve the earnout. The buyer can generally prioritize its own business interests, make decisions that might negatively impact the earnout (as long as they are not made in bad faith), and is not obligated to spend extra money or resources.

Because it is a relatively weak standard, sellers usually negotiate for a higher "efforts" clause to ensure the buyer is more proactively engaged in making the earnout successful.

During negotiations, management presentations, and diligence, buyers naturally discuss their post-closing plans. A buyer might say, "We plan to inject $10 million into your marketing budget," "We intend to keep your sales team entirely intact," or "We see massive cross-selling synergies with our existing products."

If the deal closes, the buyer takes control, those plans change, and the earnout misses its target, the seller will often sue for “promissory fraud”. 

The seller will argue that they were fraudulently induced into accepting the earnout structure based on the buyer's extra-contractual promises about how the business would be supported and operated post-close.

M&A professionals often mistakenly believe that a standard "Integration" or "Entire Agreement" clause at the back of the Purchase Agreement solves this problem. It does not.

An anti-reliance provision is generally needed to ensure they are not relying on any statements, forecasts, projections, or promises outside of the express representations and warranties written in the four corners of the agreement.