Spanish statutory and late-payment interest calculator
An unpaid Spanish debt earns interest, and not every debt at the same rate. Enter the amount and the two dates and see what yours adds up to.
From 20 September 2025 to 20 September 2026: 365 days.
| Window | Days | Rate | Interest |
|---|---|---|---|
| 20 Sept 2025 | 103 | 3.25 % | €91.71 |
| 01 Jan 2026 | 262 | 3.25 % | €233.29 |
| Amount owed | €10,000.00 | ||
| Total | €10,325.00 |
- Mind the start date: article 1100 of the Civil Code requires the creditor to DEMAND payment, in or out of court, before default exists. Unless the contract or a statute says otherwise, the clock starts on the demand and not on the due date.
Video: how to use the calculator
Six different rules behind one word
When somebody does not pay, the penalty for the delay is called interés de demora in every case and is worked out in six different ways. Article 1108 of the Civil Code is the default rule of all Spanish private law: if the debt is money and no rate was agreed, the statutory rate applies. Article 576 of the Civil Procedure Act adds two points as soon as there is a judgment. Article 26 of the General Tax Act applies the statutory rate increased by 25 % to anything owed to the tax office. Ley 3/2004 takes invoices between businesses to a rate that hangs off the European Central Bank. Article 29.3 of the Workers’ Statute puts a flat 10 % on unpaid wages. And article 20 of the Insurance Contract Act punishes an insurer that will not pay with the statutory rate plus half. The calculator applies the one that fits, and the side-by-side mode puts all six on your own debt.
A budget sets the rate, and the same one has applied for four years
Article 1 of Ley 24/1984 says the statutory rate «shall be set in the State Budget Act». The last one passed is Ley 31/2022, whose 42nd additional provision fixed it at 3.25 % «until 31 December 2023». That block has exactly one version in the consolidated text and has never been amended. Article 134.4 of the Constitution automatically rolls over a budget that is not passed, and the Banco de España publishes 3.25 % for 2024, 2025 and 2026. Nobody has decided this year’s rate: it is 2023’s. That same 1984 statute opens a second route almost nobody mentions, and it has been used: the Government may revise the rate mid-year in the light of public-debt yields, and that is exactly what happened in 2009, when the statutory rate fell from 5.50 % to 4.00 % on 1 April. A debt that crosses that year is therefore split in two.
When the clock starts, which is where most people get it wrong
The start date is not the same question in the six regimes, and it is the one that moves the most money. In civil law, article 1100 of the Civil Code requires the creditor to DEMAND payment, in or out of court, before default exists: unless the contract or a statute says otherwise, the clock starts on the demand and not on the due date. On an invoice between businesses the opposite is true: article 6 of Ley 3/2004 makes interest run with no warning at all, provided the creditor performed and was not paid on time. Article 26.1 of the General Tax Act says the same of a debt to the tax office, and adds that the delay need not even be culpable. Court interest runs from the moment judgment is given at first instance, not from the moment it becomes final. And in insurance the clock starts on the date of the loss, not on the claim or on the insurer’s refusal.
The invoice between firms is the expensive case, and it has pulled away
Article 7 of Ley 3/2004 does not fix a number: it fixes an operation. The rate is the one the European Central Bank applied in its last main refinancing operation before the half-year, plus eight percentage points, and the Treasury publishes it every six months in the official gazette. In the first half of 2026 the ECB stood at 2.15 %, so the rate was 10.15 %; in the second it rose to 2.40 % and the rate is 10.40 %. While the statutory rate has been frozen since 2023 because it depends on a law nobody passes, the commercial one has moved six times over the same period because it depends on an auction held every week: a flat 8.00 % from 2016 to 2022, then 10.50, 12.00, 12.50, 12.25, 11.15, 10.15 and 10.40. The two rates diverged for the least legal reason imaginable.
Two details worth money that hardly anyone states
The first is in the closing paragraph of article 26.6 of the General Tax Act: where the debt is deferred, paid in instalments or suspended and is guaranteed in full by a bank guarantee, a mutual guarantee company or a surety insurance certificate, «the interest payable shall be the statutory rate». That is 3.25 % instead of 4.0625 %: posting a guarantee cuts the rate by 0.8125 points, and the calculator shows both figures together in the tax regime. The second is in article 8.1 of Ley 3/2004: on a late invoice the creditor is entitled to a fixed 40 € for recovery costs, added «in every case and without any express request», and may claim whatever evidenced costs exceed it on top. On a 500 € invoice paid a month late, the interest is 4.17 € and the compensation is 40 €.
Simple interest, and what the calculator does not do
The calculation uses SIMPLE interest: the interest is not compounded. The reason is article 1109 of the Civil Code, which makes accrued interest earn interest itself only «from the moment it is claimed in court», so compounding it earlier would invent a right the statute does not grant. Each window is worked out on its own calendar days and with the divisor of the year it falls in, which is 366 in a leap year. What the calculator does not do: it does not apply a contractual rate, which always beats the statutory one in the civil and commercial regimes; it does not price a loan’s remuneratory interest, which is a different thing; it does not decide whether an agreed rate is usurious; and on a tax debt it works out neither surcharges nor penalties, which belong to articles 27 and 191 onwards of the General Tax Act.
Worked example
A debt of 10,000 € demanded on 20 September 2025 and paid on 20 September 2026. At the statutory rate that is 325.00 €, because 3.25 % of 10,000 € over 365 days is exactly that. With a judgment it would be 525.00 €; owed to the tax office, 406.25 €, or 325.00 € with a bank guarantee; as unpaid wages, 1,000.00 €; as an invoice between firms, 1,020.55 € plus a fixed 40 €. Same money, same dates, and more than a threefold gap between the first figure and the last.
Frequently asked questions
What is the Spanish statutory interest rate in 2026?
And the tax late-payment rate?
From which day is the interest counted?
Can I charge more than this if the contract says so?
Does the interest itself earn interest?
Why does an invoice between firms cost three times as much?
What is the 40 € that appears in the commercial regime?
Why is a debt crossing 2009 split into two windows?
What if my insurer takes more than two years to pay?
Can I use this to work out the interest on a loan?
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Sources
- Código Civil, artículos 1100, 1108 y 1109: la mora exige reclamación salvo pacto o ley en contra, la indemnización por deuda de dinero es «el interés legal» a falta de convenio, y los intereses vencidos sólo devengan interés «desde que son judicialmente reclamados» · Boletín Oficial del Estado
- Ley 24/1984, de 29 de junio, artículo primero: «El interés legal del dinero se determinará en la Ley de Presupuestos Generales del Estado», y su párrafo segundo permite al Gobierno revisarlo dentro del ejercicio atendiendo a la Deuda Pública · Boletín Oficial del Estado
- Ley 31/2022, disposición adicional cuadragésima segunda: el interés legal «queda establecido en el 3,25 por ciento hasta el 31 de diciembre del año 2023» y el de demora tributaria en el 4,0625 por ciento · Boletín Oficial del Estado
- Banco de España, Portal del Cliente Bancario: la tabla oficial de tipos de interés legal por año, que publica 3,25 % para 2024, 2025 y 2026, y los dos tramos de 2009 · Banco de España
- Ley 58/2003, General Tributaria, artículo 26: el interés de demora «no requiere la previa intimación», no corre mientras la Administración incumple sus plazos, es el legal «incrementado en un 25 por ciento» y baja al legal con aval solidario o seguro de caución · Boletín Oficial del Estado
- Ley 3/2004, de lucha contra la morosidad, artículos 6, 7 y 8: el interés corre sin aviso, el tipo es el del BCE más ocho puntos por semestre, y el acreedor cobra además 40 € fijos «sin necesidad de petición expresa» · Boletín Oficial del Estado
- Resolución de 30 de junio de 2026 de la Secretaría General del Tesoro: el BCE aplicó el 2,40 % el 30 de junio, así que el tipo comercial del segundo semestre de 2026 es el 10,40 por 100 · Boletín Oficial del Estado
- Ley 1/2000 de Enjuiciamiento Civil, artículo 576: la mora procesal es el interés legal más dos puntos desde la sentencia de primera instancia, y alcanza a los laudos arbitrales y a los acuerdos de mediación · Boletín Oficial del Estado
- Estatuto de los Trabajadores, artículo 29.3: «El interés por mora en el pago del salario será el diez por ciento de lo adeudado» · Boletín Oficial del Estado
- Ley 50/1980 de Contrato de Seguro, artículo veinte: la mora del asegurador se impone de oficio, corre desde el siniestro al interés legal más el 50 %, y pasados dos años «no podrá ser inferior al 20 por 100» · Boletín Oficial del Estado
Author: Thorben Rasmus Idel · Reviewed by: Nahar Geva · Last reviewed: