Solutio Indebiti: Meaning

See Article 2154. Article 2155 adds that a payment made because of "a mistake in the construction or application of a doubtful or difficult question of law" may also come within this rule.

There is no agreement between the payer and the receiver. The obligation is created by law. Article 2142 says quasi-contracts arise from certain lawful, voluntary and unilateral acts "to the end that no one shall be unjustly enriched or benefited at the expense of another."

In BDO Unibank v. Barcellano (2026), the Supreme Court said the obligation to reimburse arises when "(1) payment is made when there exists no binding relation between the payor, who has no duty to pay, and the person who received the payment; and (2) payment is made through mistake, not through liberality or some other cause."

A payment made out of generosity is not covered. A payment made because of an existing debt is not covered either, because the receiver had a right to demand it.

• Interest paid without a written agreement. Article 1960 says that when a borrower pays interest with no stipulation for it, the rules on solutio indebiti or natural obligations apply, as the case may be. In Siga-an v. Villanueva (2009), the Court said "The payment was clearly a mistake," and ordered the lender to return the interest. See Is 5% monthly interest legal?.
• Bank credit by mistake, receiver knew. In Yon Mitori v. Union Bank (2020), a depositor withdrew the value of a check credited early by error, knowing he was not entitled to it. His obligation "to return the erroneously credited funds" to the bank stood.
• Bank credit by mistake, payer at fault. In BDO (2026), the bank was grossly negligent, and the depositor could reasonably believe in good faith that the money was hers. The Court held that "the principle of solutio indebiti does not apply in this case."

The cases read involved banks or a lender. None involved a mistaken transfer between two private persons, so each case depends on its facts.

Made-up illustration: Dodong's employer pays his monthly bonus twice by mistake. Dodong had no right to the second payment, and the employer paid it through an error, not as a gift. Under Article 2154, Dodong has an obligation to return the extra amount. If a court case is filed, the court looks at the evidence, including what each side knew and did. See Money sent to the wrong account.