Past consideration is the contract-law rule that a promise given in return for something the other person already did is usually not enforceable. Contract law requires both sides to exchange something of value at the moment the deal is formed. When one person’s contribution happened before the promise existed, that earlier act cannot serve as the legal glue for the later promise, no matter how sincere the promise or how real the earlier benefit.
Why Timing Is the Whole Problem
Consideration is about a trade. The Restatement (Second) of Contracts defines it as a performance or return promise “sought by the promisor in exchange for his promise and given by the promisee in exchange for that promise.” You act because the other person promised something; they promised because you agreed to act. That two-way inducement is the bargain.
Past consideration fails this test because the act was already finished before any deal was proposed. Paint a neighbor’s fence on Saturday, and a Monday promise of $200 is not what moved you to pick up the brush. The offer did not exist yet. A court sees a completed favor followed by a separate, one-sided promise, not a negotiated exchange.1Legal Information Institute (LII). Consideration
The law treats that after-the-fact promise as a proposed gift. Gifts, however clearly stated, are not enforceable contracts. The promisor can change their mind, and the person who performed the earlier act has no breach-of-contract claim. The clash with intuition is sharp: a clear, specific promise can be legally empty because the current exchange is missing.
Where This Trips People Up
Retroactive Bonuses
Employers run into this constantly. A manager announces after a record quarter that everyone will get a $5,000 bonus for excellent work. The employees already did the work under their existing pay agreements. They took on no new tasks in exchange for the bonus promise, because the promise did not exist when they performed. If the company later pulls the bonus, employees generally cannot sue for breach of contract.
Framing fixes it. Promise a bonus tied to hitting targets next quarter, and employees have something new to do in exchange. The same $5,000 lands on opposite sides of the enforceability line depending on sequence.
Rewards Discovered After the Fact
Someone finds a lost dog, returns it, and only then learns about a $500 reward. If the owner refuses to pay, the finder has no contract claim. Returning the dog was not done in exchange for a reward the finder didn’t know about. Even if the owner says “I’ll pay you the $500” after the dog is home, that statement rests on a completed act and reads as a gratuitous promise.
Non-Competes Added After Hiring
When an employer asks a current employee to sign a non-compete months or years into the job, the question becomes whether the employee is getting anything new in return. The original decision to take the job is past consideration for the new restriction. States are split on whether continued at-will employment, by itself, counts as fresh consideration. A majority accept it; a meaningful number do not, and some that once accepted it have reversed through legislation. Where continued employment isn’t enough, the employer needs to add something tangible like a raise, a bonus, or access to new training.
The Narrow Exceptions That Can Still Enforce a Promise
The Material Benefit Rule
The broadest exception comes from the Restatement (Second) of Contracts, Section 86. A promise made to someone who previously conferred a real, tangible benefit on the promisor can be enforced “to the extent necessary to prevent injustice.” It is not a blank check. Two conditions block enforcement: the benefit was intended as a gift, or the promised amount is wildly out of proportion to what was received.
The classic case is Webb v. McGowin (1935). Webb, working in a lumber mill, saved McGowin’s life by falling with a heavy block to divert it, leaving himself permanently disabled. McGowin promised to pay Webb $15 every two weeks for the rest of Webb’s life, and paid for eight years until he died. When the estate tried to stop the payments, the court enforced the promise. McGowin had received a concrete, life-saving benefit; Webb had suffered enormously providing it; the amount was proportionate.
Section 86 does not reach every promise tied to a past act. If the earlier benefit went to a third party rather than to the promisor, the rule generally does not apply.
Debts Past the Statute of Limitations
When a debt ages past the statute of limitations, the creditor loses the right to sue, but the underlying obligation does not vanish. Under the Restatement (Second) of Contracts, Section 82, a new promise to pay the time-barred debt is enforceable. A written acknowledgment or a partial payment can restart the creditor’s ability to pursue the full amount. The original exchange of value happened; the statute of limitations is a procedural defense the debtor can waive.
This catches people off guard. A letter saying “I know I still owe you $3,000 and I plan to pay it” can revive a debt that was otherwise uncollectible. Anyone contacted about an old debt should know that acknowledging it in writing, or making even a small payment, can carry real legal consequences.
Debts Reaffirmed After Bankruptcy
Under the Restatement (Second) of Contracts, Section 83, an express promise to pay a debt that was discharged or dischargeable in bankruptcy is binding. In practice this is done through a reaffirmation agreement filed with the bankruptcy court. Federal law imposes strict requirements: specific disclosures to the debtor, an attorney’s certification that the agreement is voluntary and not an undue hardship, and a 60-day window after filing for the debtor to rescind.2Office of the Law Revision Counsel. United States Code Title 11 – 524
If the debtor was not represented by an attorney in negotiating the reaffirmation, the court must independently approve it as being in the debtor’s best interest and not creating undue hardship.2Office of the Law Revision Counsel. United States Code Title 11 – 524 Reaffirming gives up part of the fresh start bankruptcy was designed to provide, so it is usually weighed against whether the creditor relationship is worth preserving (often to keep a car or home tied to the debt).
Contracts Signed as a Minor
Contracts signed by minors are generally voidable. Once the person reaches the age of majority, they can ratify the earlier agreement and make it binding. Ratification can be explicit, like a written confirmation, or implied by continuing to pay or use the goods without objection. Failing to disaffirm within a reasonable time after turning 18 can itself count as ratification. The original exchange of value did occur; the law simply lets the now-adult party remove the defense that previously made the contract unenforceable.
Moral Obligation Is Not Legal Obligation
A common misreading of the material benefit rule is that any moral obligation can support a promise. It cannot. Feeling grateful, indebted, or duty-bound does not create consideration. A promise to pay a neighbor for unsolicited yard work done during a vacation may reflect a genuine sense of obligation, but the neighbor acted without any prior arrangement. The law sees a gift of labor followed by a separate expression of gratitude.
Courts draw this line on purpose. If moral obligation alone could turn a promise into a contract, almost any expression of thanks could trigger a lawsuit. Enforcement is reserved for situations where the conduct genuinely resembles a transaction.
A Related Trap: Modifying a Contract for Work Already Owed
Past consideration overlaps with the pre-existing duty rule. If you are already contractually obligated to do something, promising to do that same thing again is not new consideration. A contractor who signed on to build a deck for $10,000 cannot demand $12,000 midway by threatening to walk off. The homeowner’s promise of extra pay is unsupported because the contractor was already required to finish.3Legal Information Institute (LII). Pre-Existing Duty Doctrine
Two carve-outs soften this. The Restatement (Second) of Contracts, Section 89, allows modifications without new consideration when unanticipated circumstances make the original terms unfair; if the contractor hits solid rock and excavation costs triple, a renegotiated price can hold. For contracts involving the sale of goods, the Uniform Commercial Code goes further and requires no new consideration at all for a modification, as long as both parties agree in good faith.4Legal Information Institute (LII). UCC 2-209 – Modification, Rescission and Waiver For services contracts, you generally still need new consideration on both sides.
What You Can Still Try When Consideration Fails
Promissory Estoppel
When past consideration kills a breach-of-contract claim, promissory estoppel can offer another path. It does not require traditional consideration. It requires three things: reasonable reliance on the promise to the promisee’s detriment, foreseeability of that reliance by the promisor, and enforcement being necessary to avoid injustice.5Legal Information Institute (LII). Promissory Estoppel
Picture an employer who promises a long-time employee a $20,000 retirement bonus. Relying on it, the employee turns down a competing job offer and retires. A breach-of-contract claim fails because years of service are past consideration. A promissory estoppel claim can succeed if the employee shows a costly, irreversible decision made in reliance on the promise. Recovery is often limited to reliance damages rather than the full promised amount, but partial recovery beats none.
Unjust Enrichment
When someone receives a benefit they did not pay for and keeping it would be unfair, a court can order payment under unjust enrichment. The remedy, historically called quantum meruit, awards the market value of the services or goods provided. It requires no proof of a promise, only proof that the recipient received something valuable, that keeping it without paying would be unjust, and that the provider did not intend a gift.
The claim is strongest when the recipient actually asked for the services. A business that asks a consultant for a report and then refuses to pay because no formal contract was signed can still be made to pay reasonable market value. When the benefit was unsolicited, courts tend to award the smaller end of a reasonable range rather than full market price.
How to Keep This From Happening
Most past consideration disputes come from timing, and most are avoidable with better documentation.
- Put the promise in writing before the work starts. A signed agreement, or even a short email exchange confirming terms, establishes the bargained-for exchange at the right moment.
- If you want to reward work already done, pair the payment with a new obligation. A bonus for last quarter becomes enforceable when it also requires the employee to stay through the next quarter or take on a new project.
- Treat old debt contacts carefully. In many states, a written acknowledgment or a partial payment on a debt past the statute of limitations can revive the creditor’s right to sue. Do not confirm the debt in writing without understanding the consequences in your state.
- Add non-competes at hire, or pair later ones with something new. Where continued at-will employment is not enough on its own, add a raise, a promotion, equity, or proprietary training.
Past consideration is a doctrine that punishes good intentions. Someone who performs a real service and then receives a sincere promise of payment has every reason to think a deal exists. Without the right sequence, the law sees a gift followed by a wish. The gap between an enforceable contract and an empty promise usually comes down to whether anyone wrote the terms down before the work began.