The Social Security regularisation letter: how the autónomo quota is squared with your real income

Every month of 2025 you paid Social Security a quota you had chosen yourself, on a forecast of what the year would bring. The forecast is now a fact: the income tax return filed this spring says what the activity really earned, and the Treasury of the Social Security sets one against the other. The result reaches you as a notification with one of three answers: money back, money owed, or nothing. The first two rounds came in winter (the one for 2023 began in December 2024, the one for 2024 in January 2026), and for 2025 the Treasury had published no date when this note was written. The arithmetic, though, is fixed by law, and with last spring's return on the table you can do it today. This note walks through it with a worked example and ends with what can still be changed before the year closes. Quotations are in Spanish with the reading in English.

A quota that is provisional until the tax return speaks

Since 2023 the self-employed cotizarán en función de los rendimientos anuales obtenidos en el ejercicio de sus actividades económicas, empresariales o profesionales, pay contributions according to the annual returns obtained from their economic, business or professional activities (General Social Security Act, texto refundido approved by Real Decreto Legislativo 8/2015, article 308). Nobody knows those returns in January, so the Act works in two steps. During the year each autónomo chooses a monthly base from a table, according to what he expects to earn, and the bases chosen tendrán carácter provisional, hasta que se proceda a su regularización, are provisional until they are regularised. The second step comes when the year's returns are known, una vez obtenidos y comunicados telemáticamente por la correspondiente Administración tributaria a partir del año siguiente, once obtained and reported electronically by the tax administration from the following year on.

There is nothing to file. The Treasury's own page, on its Importass portal, says it in one line: No es necesario que presentes una solicitud, you do not need to submit an application. For 2024 the comparison was made for everyone who had been registered for at least one day of the year, and the answer arrived on its own.

The figure the Treasury starts from

It is not the figure most people call their profit. For an activity taxed by direct estimation, el rendimiento computable será el rendimiento neto, incrementado en el importe de las cuotas de la Seguridad Social y aportaciones a mutualidades alternativas del titular de la actividad, the computable return is the net return plus the Social Security contributions and the payments to alternative mutual funds of the owner of the activity. In the tax return those are two boxes, 0224 and 0186, as the Tax Agency's page on the new system explains; an activity on modules, outside farming, uses the «rendimiento neto previo» of box 1465 instead. Every activity counts, including one carried on through a company or a partnership.

From that sum the Act takes una deducción por gastos genéricos del 7 por ciento, a deduction of 7 per cent for generic expenses, or 3 per cent for those registered through a company they control. What is left is turned into a monthly figure by the regulation: it se dividirá entre el número de días en situación de alta calculados conforme a la regla 1.ª y se multiplicará por 30, is divided by the number of days registered, calculated under rule 1, and multiplied by 30 (Real Decreto 2064/1995, article 46). That monthly figure, and nothing else, decides the tranche.

The table for 2025

The year being settled is 2025, so the table is the one the contribution order fixed for that year (Orden PJC/178/2025, article 18). Each tranche of monthly return has a minimum base and a maximum one.

The table for 2026 keeps the same tranches and the same minimum bases; the ceiling rises from €4,909.50 to €5,101.20 (Orden PJC/297/2026, article 18).

Three outcomes

The Treasury compares the average base you paid on during the year with the tranche your return lands in.

If the average sits between the minimum and the maximum of that tranche, nothing moves: no procederá la regularización de las bases de cotización y cuotas provisionales, pasando a tener estas la condición de definitivas, the provisional bases and quotas are not regularised and become final.

If it is below the minimum, the final base is that minimum and the difference is owed. It can be paid hasta el último día del mes siguiente a aquel en que se le notifique el resultado de la regularización, sin aplicación de interés de demora ni recargo alguno de abonarse en ese plazo, until the last day of the month following the one in which the result is notified, with no late-payment interest and no surcharge if it is paid within that period.

If it is above the maximum, the final base is that maximum and the Treasury returns the difference on its own initiative, antes del 30 de abril del ejercicio siguiente a aquel en que la correspondiente Administración tributaria haya comunicado los rendimientos computables, before 30 April of the year following the one in which the tax administration reported the computable returns. For returns reported during 2026, that is 30 April 2027.

In both directions the difference in base is charged at the rates of the year being settled, not at today's: se aplicarán a dichas diferencias los tipos y demás de condiciones de cotización correspondientes a los períodos de liquidación objeto de regularización, the rates and other contribution conditions of the periods regularised apply to those differences. For 2025 the rates add up to 31.40 per cent: 28.30 for common contingencies, 1.30 for professional ones, 0.90 for cessation of activity, 0.10 for training and 0.80 for the intergenerational equity mechanism. In 2026 the last of them is 0.90, and the total 31.50.

The quota you paid in 2025 was an advance. The tax return you filed in spring is the bill.

A worked example: €1,900 a month on the minimum base

A physiotherapist on the island paid the whole of 2025 on the lowest base of the general table, €950.98, which is €298.61 a month and €3,583.32 for the year. Her tax return shows a net return of €21,300 after deducting those contributions.

The Treasury adds the contributions back: €24,883.32. It takes off 7 per cent: €23,141.49. It divides by 365 days and multiplies by 30: €1,902.04 a month. That is the tranche that runs from over €1,850 up to €2,030, and its minimum base is €1,209.15.

She paid on €950.98, so her base was €258.17 a month short. At 31.40 per cent that is €81.07 a month, about €973 for the year, payable by the end of the month after the notification with nothing added.

The sum runs the other way just as easily. An autónomo who paid all year on a base of €1,500 and whose return works out at €1,000 a month falls in the tranche whose maximum base is €1,166.70. The Treasury returns the quota on the €333.30 a month in between: about €105 a month, some €1,256 for the year.

Who is outside, and who has rules of their own

• The flat rate. La cuota reducida no será objeto de regularización, the reduced quota is not regularised, during its first twelve months; in the second twelve it is left alone only if the year's net returns stayed below the annual minimum wage (Ley 20/2007, article 38 ter).
• Months that already counted for a benefit. A month whose base was used to calculate a benefit granted before the regularisation, sick pay or maternity leave among them, keeps that base, and so do the months in which the benefit was drawn.
• Those who were paying more before 2023. Autónomos who on 31 December 2022 paid on a base higher than their returns warranted podrán mantener dicha base de cotización, o una inferior a esta, aunque sus rendimientos determinen la aplicación de una base de cotización inferior a cualquiera de ellas, may keep that base, or a lower one, even if their returns point to a base lower than either (Real Decreto-ley 13/2022, transitional provision six). In the last round they were notified first, and they have until the last day of the following month to say that they keep it, which means giving up the refund.
• Company directors and family collaborators. Their floor is not the table's: €1,000 a month for 2025 and, from 2026, the minimum base of contribution group 7 of the general scheme, €1,424.40, which the Treasury has announced it will apply when 2026 is regularised even to those who kept paying on €1,000 during the year. Whether a company is still the better vehicle is the subject of our note on autónomo or SL.
• No tax return, or no income declared under direct estimation. The final base is then that same floor, whatever was earned.

The letter is not a letter

Nothing comes through the post. The Treasury's page says the notification arrives through the Social Security's electronic notification service and the DEHú portal, and asks you to keep your e-mail address up to date. The general rule of administrative procedure is that an electronic notification which is compulsory, or was chosen by the person concerned, se entenderá rechazada cuando hayan transcurrido diez días naturales desde la puesta a disposición de la notificación sin que se acceda a su contenido, is deemed rejected once ten calendar days have passed since it was made available without its content being opened, and a rejected notification counts as made: the procedure carries on (Ley 39/2015, articles 41 and 43). The month for paying does not wait for you to look.

If the result is to pay, the resolution states the amount and the date, and the payment document is attached to it in the regularisation service. Pay late and, in the Treasury's words, un recargo del 10% o 20% applies, a surcharge of 10% or 20%. If the result is a refund, it goes to the bank account the Treasury has on file, which is the other thing to keep up to date.

And in the income tax return

The Tax Agency's manual for the 2025 return settles the question that follows. The quotas paid during the year were cantidades legalmente debidas aunque provisionales, amounts legally due although provisional, so the return of that year is not amended. An extra amount paid after the regularisation is a mayor gasto deducible, a larger deductible expense, of the year in which it is paid (box 0196); a refund reduces that year's expense (box 0197), and if it is larger than the quotas paid in the year, the excess is income (box 0178). Those two boxes then enter the Treasury's own sum for that later year, next to boxes 0224 and 0186.

Before the year closes

• Do the sum with the 2025 return. Boxes 0224 and 0186, less 7 per cent, divided by 365 and multiplied by 30 if you were registered all year. Compare the result with the table and with the base you paid on.
• Set the difference aside, or expect it back. The bill comes with a month to pay, and the refund has a legal deadline of its own.
• Correct 2026 while it can be corrected. The self-employed podrán cambiar hasta seis veces al año la base por la que vengan obligados a cotizar, may change up to six times a year the base on which they must contribute: a request made by 31 October takes effect on 1 November, and one made in November or December on 1 January (Real Decreto 2064/1995, article 45). The comparison is made with the average base of the whole year, so every month paid on a truer base shrinks next year's difference.
• Keep the channel open. The e-mail address and the bank account that Importass holds are the ones the Treasury will use.

What our advisers do

Our tax advisers in Caleta de Fuste and Costa Calma prepare the income tax return this calculation starts from and look ahead in December, while moves still fit in the year; the base for the months to come is one of them. The labour desk handles the Social Security filings and, for those with staff, the employer's side, whose cost is set out in our note on what an employee really costs. The services are described on the tax advisory and labour advisory pages, and a first meeting can be booked online.

Common questions

When will the notification for 2025 arrive?

The Treasury had published no date when this note was written. The round for 2023 began in December 2024 and the one for 2024 in January 2026, the second announced in a bulletin dated 22 December 2025. The notification is electronic, so the place to look is the Social Security's notification service or DEHú.

Do I have to apply for the refund?

No. The Treasury makes the comparison for everyone and returns what is owed to the bank account it has on file. The only step that needs your answer is the one offered to those who paid on a higher base before 2023 and want to keep it.

What happens if I do not pay on time?

The difference carries no interest and no surcharge if it is paid by the last day of the month after the notification. After that the Treasury's page speaks of a surcharge of 10% or 20%, and the debt is claimed through the ordinary collection procedure.

I am on the flat rate. Does this affect me?

Not during the first twelve months. In the second twelve the reduced quota is regularised only if your net returns for the year reach the annual minimum wage, and then the benefit for that year is lost.

Does the extra payment change my tax return for 2025?

No. The Tax Agency treats it as a deductible expense of the year in which you pay it, in box 0196, and a refund as a smaller expense of the year in which you receive it. The 2025 return stays as it was filed.

Facts verified in October 2026 (texto refundido de la Ley General de la Seguridad Social, article 308; Real Decreto 2064/1995, articles 44 to 46; Real Decreto-ley 13/2022, transitional provisions six and seven; Ley 20/2007, article 38 ter; Ley 39/2015, articles 41 and 43; Orders PJC/178/2025 and PJC/297/2026, articles 18 and 37; the Treasury's Noticias RED bulletins 12/2025 and 5/2026 and its Importass page on the regularisation; the Tax Agency's manual for the 2025 income tax return and its page on the returns it reports to the Treasury, all as they read on 4 October 2026). The physiotherapist and the figures of the examples are illustrative; this is general information, not advice on your case.