What happens when a debt is sold?

What changes and what does not

Selling a debt is what the law calls an assignment of debt (“cesión de crédito”), that is, the creditor transfers their right to be paid to someone else. It is an agreement between the old creditor and the new one, which does not require the debtor's consent. The “Código Civil de Cataluña”, the Catalan Civil Code, does not regulate assignment, so the Spanish Civil Code (“Código civil”) applies, just as in most of the rest of Spain. As the publication explains, in January 2026 the “Tribunal Supremo”, Spain's Supreme Court, pointed out that assignment does not create a new obligation and that the claim retains its nature. In practice, that means:

• The new creditor cannot claim more than was owed or change the interest, the payment deadlines or the other terms.
• The guarantees pass to them too, such as a guarantor's personal guarantee or a mortgage. If the debt is secured by a mortgage, the assignment is made by public deed and registered at the “Registro de la Propiedad”, the Land Registry.
• The sale does not make the limitation period start again. The existing one continues to run, although a claim by the new creditor does interrupt it.

When you have to pay the new creditor

The law protects a debtor who does not know that their debt has been sold. If they pay the old creditor before finding out, the payment is valid and they are discharged. Once they know of the sale, however, they have to pay the new one. That is why the debtor is usually notified in writing. If a new creditor writes to you:

• Ask them to prove that they have bought the debt and to give you a breakdown of what they are claiming, showing the capital, the interest and the payments already deducted.
• Do not pay twice. If you have already paid something to the old creditor, keep the receipt and rely on it.
• You can raise against them the same defences that you had against the previous creditor and that affect the debt, such as that it has been partly paid, that it is time-barred, that it has not yet fallen due, that the contract is void or that it contains unfair terms.
• Set-off, which means deducting what the old creditor owed you, has its own rules. If you accepted the sale, you can no longer do so against the new creditor. If you did not accept it but were notified of it, you can deduct the old creditor's debts to you that arose before the sale. If you knew nothing about the sale, you can also deduct later ones, up to the time you found out.

If you are the one selling what another private individual owes you, the same rules apply and it is advisable to notify the debtor in writing.

If the debt was already the subject of court proceedings

There is a special case, the so-called right of redemption of a litigious claim (“retracto de crédito litigioso”). If the debt is sold when it is already being disputed in court proceedings, the debtor can extinguish it by paying the buyer the same amount that the buyer paid for it, plus the costs the buyer has incurred and interest on that price. It is subject to strict limits:

• The debt is only regarded as litigious once the debtor has filed a defence to the claim.
• It must be exercised within nine days of the buyer demanding payment.
• The Supreme Court interprets it restrictively. It only applies if the proceedings dispute whether the debt exists or can be enforced, not when the only dispute is over a clause, such as a mortgage floor clause (“cláusula suelo”).
• According to the same case law, it does not apply when the debt is sold together with many others in a portfolio for a global price, which is the usual practice when a bank sells debts to a fund.