Short answer. Yes. The Civil Code states that the responsibility of two or more payees when there has been payment of what is not due is solidary. You can demand the full amount back from either one of them, without having to chase each person for their individual share.
What the law says
The responsibility of two or more payees, when there has been payment of what is not due, is solidary.
Civil Code, Article 2157 — Solidary Liability of Payees. Read the full provision →
The rule on undue payment to multiple recipients
Article 2157 of the Civil Code is brief and direct: the responsibility of two or more payees, when there has been payment of what is not due, is solidary. Payment of what is not due — called solutio indebiti in civil law — creates an obligation on the part of whoever received it to return it. When two people receive that mistaken payment, neither can hide behind the other and say "you only paid me half, so only demand half from me." Each is liable for the entire amount.
What solutio indebiti means
When you pay money that was not owed — whether because the debt did not exist, the debt was already paid, or you paid the wrong people — the law treats this as a quasi-contract. The recipients are unjustly enriched at your expense and are required to return what they received. It does not matter whether they acted in good faith or knew you were mistaken. The obligation to return arises from the simple fact of receiving payment that was not due to them. You are the one who suffered the loss, and the law gives you a right to recover it.
Solidary liability: collecting from either or both
Because the liability is solidary, you have real options in how you pursue recovery. You can demand the full amount from the first payee alone, from the second payee alone, or from both simultaneously. Whichever payee you collect from first satisfies the obligation — the other is then released from the claim to the extent already recovered. The payees must sort out their internal shares between themselves; that arrangement does not concern you. If you cannot locate one of them or one refuses to pay, you go after the other for everything.
What you need to prove and how to act
To enforce your right to recover, you need to establish three things: that you paid, that the payment was not owed, and that these two people received it. Documentation helps — bank transfers, receipts, witness accounts of the payment. Start with a written demand to both recipients, clearly stating the mistake and requesting return of the amount. If they refuse or ignore you, the action for recovery can be brought in court. Keep in mind that there may be a prescriptive period within which you must act, so do not delay once you realize the mistake was made.