What this letter is
Since 2023, autónomos (self-employed workers) pay contributions based on their actual income. Each year you choose a provisional base according to what you expect to earn. When Hacienda (the tax authority) reports your actual rendimientos (net business income) to Social Security, the Tesorería General (TGSS) (General Treasury) carries out the regularización (adjustment): it calculates your final base and tells you whether you paid too little or too much (art. 308.1.c LGSS). This letter is that decision.
How to read it: the key parts
| What you see on the letter | What it means |
|---|---|
| Resolución de regularización / Ejercicio (adjustment decision / year) | The year being adjusted. |
| Rendimientos computables (countable income) | What Hacienda says you earned from your business, with Social Security’s adjustments. |
| Deducción por gastos genéricos (7 % or 3 %) (deduction for general expenses) | A fixed discount on your income. The 3 % applies to self-employed company directors or partners. |
| Tramo and base de cotización definitiva (income band and final contribution base) | The band of the table that applies to you and the monthly base used. |
| Bases provisionales (provisional bases) | The bases you contributed on during the year. |
| Diferencia a ingresar (difference to pay) | What you have to pay. |
| Diferencia a devolver (difference to refund) | What is refunded to you automatically. |
| Plazo and Pie de recursos (deadline and appeals note) | Until when to pay and how to challenge it. |
If your provisional base was between the minimum and maximum of your band, there is nothing to pay or refund.
What deadline you have
If you have to pay: you have until the last day of the month after notification, with no surcharge or interest.
Example: you are notified on 18 October. You can pay until 30 November.
If you get a refund: you don’t need to do anything. The TGSS refunds it before 30 April of the year after Hacienda’s report.
Self-employed workers receive Social Security notifications electronically. If you don’t open the notification within 10 calendar days, it is treated as delivered and the deadline starts anyway.
What you can do
| Option | When it makes sense | What happens next |
|---|---|---|
| Pay the difference | If the details are correct | It’s closed, with no surcharge. |
| Wait for the refund | If you are owed money | It’s paid into your account, without interest. |
| Review and correct your tax return | If the income is wrong because of your return | Correct it with Hacienda and then ask for the refund. |
| Appeal the decision | If Social Security got the calculation wrong | Check the deadline in the appeals note. |
| Ask for a deferral (aplazamiento) | If you can’t pay all at once | A payment plan with interest. |
| Do nothing | If you owe money, never | Surcharge, debt claim and enforced collection. |
What happens if you do nothing
- If you owe money and don’t pay on time, the difference becomes a debt with a recargo (surcharge) and interest.
- You will receive a reclamación de deuda (debt claim) or a providencia de apremio (enforcement notice).
- You stop being up to date with your payments and it can end in an embargo (seizure).
- Surcharges and interest are never refunded, even if your income changes later.
Common mistakes
- Confusing income with turnover. What counts is net income, not what you invoice.
- Not filing your tax return: they apply a minimum base that may leave you with something to pay.
- Thinking you have to ask for the refund. It’s automatic.
- Not checking electronic notifications and missing the surcharge-free deadline.
- Not adjusting the current year’s base and repeating the same difference.
How to respond, step by step
- Open the notification on the Social Security online portal (sede electrónica) or in Import@ss, with Cl@ve or a certificate.
- Compare the income with your tax return for that year.
- If you have to pay: download the payment document and pay before the last day of the following month. Keep the receipt.
- If you get a refund: check that your bank account is correct in Import@ss.
- If there’s an error: correct your tax return with Hacienda or appeal the decision through the electronic registry, with evidence.
- Review your current contribution base and change it if your income has changed.
Cartamiga tip: note the deadline as soon as you open the letter. If you pay before the last day of the following month, there’s no surcharge. And adjust your base every year so the next adjustment doesn’t catch you by surprise.