Spain Law 3/2004 — Late Payment Interest for Foreign Creditors

A foreign supplier holding overdue invoices on a Spanish counterparty rarely realises that Spanish statute already calculated the late-payment interest for them, set the floor, and made it automatic. Ley 3/2004, transposing EU Directive 2011/7, imposes a punitive ECB-plus-eight-percentage-points rate, a flat EUR 40 per overdue invoice as recovery compensation, and reasonable cost recovery on top. None of it requires a contract clause. The reform under Ley 18/2022 then closed the loopholes Spanish debtors had been using to argue around it. This page covers what the statute actually grants an overseas creditor, how the calculation works on a real invoice, and how the resulting figures roll into a monitorio filing.

What Ley 3/2004 actually grants the creditor

Article 7 of Ley 3/2004 sets the statutory interest rate at the European Central Bank's main refinancing rate plus eight percentage points, recalculated every six months and published by the Spanish Ministerio de Asuntos Económicos in the BOE. For the first half of 2026 the resulting figure is 12.15% annual. The rate accrues automatically from the day after the contractual due date, without need of formal demand or a contract clause to that effect. A debtor cannot opt out by silence, by adverse general terms, or by a payment term that breaches the statutory cap.

Article 8 then adds a flat EUR 40 compensation per overdue invoice for internal recovery costs, payable without proof of damage. A creditor with twelve overdue invoices is entitled to EUR 480 of fixed compensation before any interest calculation begins. Article 8.2 extends the right to reasonable additional recovery costs above the flat sum, including legal, advisory, and external collection-agency fees, capped only by reasonableness. Spanish courts have consistently upheld these claims on monitorio petitions when documented, and the Ley 18/2022 reform made them indefeasible by contractual clause.

What changed under Ley 18/2022 and why it matters to a foreign creditor

The Ley 18/2022 reform, often called the anti-late-payment crusade, closed three loopholes that Spanish debtors had used for two decades. First, contractual clauses purporting to extend the payment term beyond 60 days for B2B transactions are now expressly null, regardless of mutual consent. Second, clauses excluding or reducing the statutory ECB+8pp interest, the EUR 40 flat compensation, or the cost-recovery right are equally void. Third, late-payment indicators are now a competitive-bidding criterion in public procurement and a transparency requirement for medium and large companies, which raises the reputational cost of slow payment beyond the financial penalty.

For an overseas creditor, the practical effect is that the calculation is no longer negotiable. A Spanish debtor arguing that the parties agreed a 90-day term, or that interest was waived in the framework agreement, is asserting a clause that Spanish statute treats as never having existed. The interest accrues, the EUR 40 attaches, and the cost-recovery right survives. The creditor's job is not to argue the principle but to execute the arithmetic correctly and present it cleanly with the monitorio petition or the burofax that precedes it.

Comparison — what statutory late-payment regimes look like across jurisdictions

A foreign creditor used to common-law jurisdictions where late-payment interest is whatever the contract says it is often underclaims on Spanish files. Spanish statute is more punitive than the contractual-default rate the parties signed, and the statutory rate prevails. When building the demand or the monitorio file, the figures should always be calculated under Ley 3/2004 first, with the contractual rate as a check rather than the basis. The same logic applies to a creditor pursuing embargo preventivo as a pre-judgment securing measure or filing a claim into a debtor's concurso de acreedores, where the principal-plus-interest figure becomes the recognised credit position.

Does the creditor need to mention Ley 3/2004 in the contract or invoice for the interest to apply?

No. The statute applies automatically by virtue of the parties being engaged in a B2B commercial transaction within or partially within Spain. There is no requirement to cite the law in the contract, the invoice, the demand letter, or the monitorio petition. A creditor should still cite the statute and the published BOE rate in the file because clarity helps the court process the petition without rejection, but the underlying right does not depend on the citation. Conversely, contractual clauses that purport to displace the statutory rate, the EUR 40 flat compensation, or the cost-recovery right are void under Ley 18/2022 and Article 9 of Ley 3/2004, regardless of whether both parties signed them.