Unjust enrichment, mistaken payments and promissory estoppel in Michigan

Michigan has no statute that names either claim, so courts borrow a period. For promissory estoppel, the Michigan Supreme Court applied the six-year contract period in Huhtala v Travelers. Courts also commonly use six years for unjust enrichment (MCL 600.5807(9), 600.5813), but one published Court of Appeals decision treats a purely equitable claim with no legal counterpart as subject to laches instead, and the Supreme Court has not squarely settled the point. Calendar the shortest period a defendant could argue.

Neither claim appears in the limitations chapter, so the question is which period a court borrows. MCL 600.5815 says the prescribed period applies equally whether legal or equitable relief is sought, and the Supreme Court has long recognized that limitations periods can apply by analogy to equitable claims (Taxpayers Allied).

Promissory estoppel is the clearer one. In Huhtala, the Supreme Court held that a promissory estoppel claim depends on contract principles and is governed by the six-year contract period, which today is MCL 600.5807(9).

Unjust enrichment is less settled. In MEEMIC v Morris, the Supreme Court analyzed an insurer's restitution claim for overpaid benefits as filed within a six-year period of limitation and held laches inapplicable for that reason. Unpublished Court of Appeals decisions, including Mashni (2023), apply six years because they treat unjust enrichment as the equitable counterpart of a contract claim; unpublished opinions are not binding. Against that, the published decision in Peabody v DiMeglio said a purely equitable unjust enrichment claim that is not based on an analogous legal claim is not governed by the contract period, and if it were time-barred it would be under laches. A defendant whose facts resemble a tort such as conversion may also argue for a shorter period, such as the 3 years in MCL 600.5805(2).

Because the Supreme Court has not squarely chosen among these, treat the earliest plausible deadline as the real one. The clock generally runs from when the wrong was done (MCL 600.5827), and Michigan does not delay it for discovery unless a statute such as MCL 600.5855 applies (Trentadue).

Authority: MCL 600.5807(9); MCL 600.5813; MCL 600.5815; MCL 600.5805(2); Huhtala v Travelers Ins Co, 401 Mich 118, 124-126 (1977); Taxpayers Allied for Constitutional Taxation v Wayne Co, 450 Mich 119, 125, 127 n 9 (1995); Michigan Educational Employees Mut Ins Co v Morris, 460 Mich 180, 198-200 (1999); Peabody v DiMeglio, 306 Mich App 397, 408 (2014); Trentadue v Buckler Lawn Sprinkler, 479 Mich 378, 388-390 (2007); Mary T Mashni Revocable Living Trust v Estate of Boulos N Mashni, unpublished per curiam opinion of the Court of Appeals, issued January 26, 2023 (Docket No. 358017); MCR 7.215(C)(1). Reviewed Oct. 2026.

Often, through an unjust enrichment claim. The Michigan Supreme Court has long recognized an equitable right of restitution when a person has been unjustly enriched at another's expense (MEEMIC v Morris). The recipient can defend by proving he or she relied on the payment to his or her detriment, and the court weighs all the circumstances, including how quickly you gave notice of the mistake.

Unjust enrichment lets you recover money someone has no good reason to keep, even without a contract. In MEEMIC v Morris, the Supreme Court said Michigan has long recognized the equitable right of restitution when a person has been unjustly enriched at the expense of another. The Court restated the principle in Wright v Genesee County (2019): unjust enrichment is a cause of action to correct a defendant's unjust retention of a benefit owed to another. In MEEMIC it quoted an older case for the point that the right to bring an action for money exists whenever a person holds money that in equity and good conscience belongs to the plaintiff, and that neither an express promise nor privity between the parties is essential.

MEEMIC involved a no-fault insurer that overpaid work-loss benefits because an earlier Court of Appeals decision had said social security benefits could not be offset, a ruling the Supreme Court later reversed. The Court recognized the insurer's equitable right to reimbursement and remanded for a determination of whether reimbursement was equitable under all the circumstances. If the recipient relied on the payment to his or her detriment, the claim can fail, and the burden of establishing that reliance is on the party opposing restitution. The Court also told the trial court to consider the timing of notice. A delay in notifying the recipient does not shorten the limitations period, but it shifts the burden to the payer to show that repayment is fair. Because the insurer sued within the six-year period, laches did not apply.

So speed and paperwork matter. Send a written demand as soon as you find the error, and keep proof of the payment and of how the mistake happened. Payments sent by wire or through a bank can also be governed by separate commercial rules.

Authority: Michigan Educational Employees Mut Ins Co v Morris, 460 Mich 180, 198-200 (1999); Wright v Genesee Co, 504 Mich 410 (2019). Reviewed Oct. 2026.

Generally no. MCL 566.132(2) bars an action against a financial institution to enforce a promise to lend, extend credit, renew or modify a loan, or waive a loan provision unless the promise is in writing and signed with an authorized signature by the institution. In Crown Technology Park v D&N Bank, the Court of Appeals held the bar applies whatever the claim is called, including promissory estoppel.

Subsection (2) of the statute of frauds is written for lenders. It says a person shall not bring an action against a financial institution to enforce a promise or commitment to lend money, grant or extend credit, or make any other financial accommodation; to renew, extend, modify, or permit a delay in repayment or performance of a loan; or to waive a provision of a loan, unless the promise or commitment is in writing and signed with an authorized signature by the financial institution. Subsection (4) defines financial institution to include state and national banks, savings institutions, credit unions, persons licensed or registered under the mortgage brokers, lenders, and servicers licensing act or the secondary mortgage loan act, and their affiliates and subsidiaries.

In Crown Technology, a borrower said a bank orally promised to waive a prepayment penalty. The Court of Appeals held the statute plainly bars a claim, no matter its label, to enforce an oral promise to waive a loan provision. It rejected promissory estoppel, and it also rejected a negligence claim that was, at its core, an attempt to enforce the same oral promise. It added that a separate claim that does not rely on enforcing the oral promise is not automatically barred.

The practical rule is to get any extension, forbearance, modification, or waiver in a signed writing from the bank before you rely on it. The opinion applied the version of subsection (2) added in 1992; The current text of subsection (2), as amended in 2020, keeps the same requirement of a writing signed with an authorized signature by the financial institution. If you already acted on an oral assurance, bring every email, text, and letter, because a writing signed by an authorized person may exist.

Authority: MCL 566.132(2), (4); Crown Technology Park v D&N Bank, FSB, 242 Mich App 538 (2000). Reviewed Oct. 2026.

Restitution, not compensation for everything you lost. In Wright v Genesee County, the Michigan Supreme Court explained that unjust enrichment is neither a tort nor a contract claim, and that its remedy is restitution that corrects a defendant's unjust retention of a benefit. A court can award money in the amount of the defendant's unjust enrichment. Because the court weighs the circumstances, a recipient who relied on the benefit can reduce or defeat recovery.

The Supreme Court described the claim in Wright v Genesee County (2019). It describes unjust enrichment as a cause of action to correct a defendant's unjust retention of a benefit owed to another, and it says the remedy is restitution. The Court contrasted that with tort and contract claims, where the remedy is compensatory damages for an injury. Quoting the Restatement of Restitution and Unjust Enrichment, it noted that a claimant entitled to restitution may obtain a judgment for money in the amount of the defendant's unjust enrichment.

That changes what you prove. A contract claim asks what you lost or what the bargain was worth. An unjust enrichment claim asks what the defendant received and kept, and whether keeping it was inequitable. The Court of Appeals describes the related quantum meruit theory the same way: the law implies a contract to prevent unjust enrichment when one party inequitably receives and retains a benefit from another (Morris Pumps). Invoices, delivery records, market rates, and proof of what the defendant saved or resold are the evidence that tends to matter.

One limit. The remedy is equitable, so courts consider the circumstances. In MEEMIC v Morris the Supreme Court said a recipient who relied on a benefit to his or her detriment can defeat restitution.

Authority: Wright v Genesee Co, 504 Mich 410 (2019); Michigan Educational Employees Mut Ins Co v Morris, 460 Mich 180, 198-200 (1999); Morris Pumps v Centerline Piping, Inc, 273 Mich App 187, 194-195 (2006). Reviewed Oct. 2026.