# Register with Social Security

> How to register as an autónomo with Social Security (alta en el RETA) in Import@ss, using the same start date as at Hacienda.

- Page: https://autonomo.eus/steps/register-social-security
- Part: Part C: Become an autónomo
- For: Everyone
- Last checked: 14 October 2026

Registering with Social Security as an autónomo (*alta en el RETA*) makes your work legal and starts your public healthcare and your monthly fee. It does not replace a work permit. **Register on the day you start, or up to 60 days before, with the same start date as at Hacienda.**

## Before you start

- [Your Social Security number](https://autonomo.eus/steps/social-security-number)
- [Your Hacienda registration](https://autonomo.eus/steps/register-hacienda) and its start date
- [Your IAE and CNAE codes](https://autonomo.eus/steps/activity-codes)
- Your bank account number (IBAN)
- Non-EU citizens: your residence and work permit, on your TIE
- Your digital ID: Cl@ve or your FNMT certificate

## What it unlocks

- Working legally as an autónomo
- [Get your health card](https://autonomo.eus/steps/health-card)
- The reduced flat fee for new autónomos

## How to do it

1. Open the Import@ss service [Alta en trabajo autónomo](https://portal.seg-social.gob.es/wps/portal/importass/importass/Categorias/altas%2C+bajas+y+modificaciones/altas+y+afiliacion+de+trabajadores/alta_trabajo_autonomo) (registration as a self-employed worker), press "Solicitar alta" (apply for registration) and log in with Cl@ve or your FNMT certificate. Inside Import@ss, the service is under "Servicios" > "Altas, bajas y modificaciones" > "Afiliación y altas de trabajadores".
2. Enter your start date: the same date as on your Hacienda registration. Your fees start on this date.
3. Enter your IAE and CNAE codes. For the IAE, also choose the tax office where you registered: your Hacienda Foral, not the AEAT.
4. Enter the address where you will work.
5. Declare the average monthly net income you expect. This sets your fee bracket. Then choose your contribution base inside that bracket.
6. Ask for the reduced flat fee (*tarifa plana*) if you qualify.
7. Choose a *mutua colaboradora con la Seguridad Social*, the body that covers you for work accidents and work-related illness.
8. Enter your contact details and the IBAN for the monthly direct debit. If the account is not in your name, you also need the holder's ID and authorisation.
9. Check every screen, confirm, and download your proof of registration (*justificante*). Import@ss also saves a copy in your documents folder.

## Where

Online at [Import@ss: Alta en trabajo autónomo](https://portal.seg-social.gob.es/wps/portal/importass/importass/Categorias/altas%2C+bajas+y+modificaciones/altas+y+afiliacion+de+trabajadores/alta_trabajo_autonomo). The same page has a "Calcular cuota" (work out the fee) button. For questions about your registration or fees, call the TGSS (*Tesorería General de la Seguridad Social*) on 915 410 291 or 901 502 050, Monday to Thursday 9:00 to 18:00 and Friday 9:00 to 14:30. For other ways to get help, see [how to contact Social Security](https://autonomo.eus/steps/offices#contact-social-security).

## Cost and time

- Cost: your monthly fee. See [Understand your monthly fee](https://autonomo.eus/steps/monthly-fee).

## Common mistakes

- A different start date from your Hacienda registration.
- Registering late. After 30 days you use [a different Import@ss service](https://portal.seg-social.gob.es/wps/portal/importass/importass/Categorias/altas%2C+bajas+y+modificaciones/altas+y+afiliacion+de+trabajadores/alta_trabajo_autonomo/fp_reta). Your registration then counts from the 1st of the month, you lose the flat fee and you pay a surcharge. Back fees use a base of €950.98 a month in 2026.

## Official sources

- [Social Security: guide for autónomos](https://portal.seg-social.gob.es/wps/portal/importass/importass/Colectivos/trabajo+autonomo/guia)
- [Import@ss: Alta en trabajo autónomo](https://portal.seg-social.gob.es/wps/portal/importass/importass/Categorias/altas%2C+bajas+y+modificaciones/altas+y+afiliacion+de+trabajadores/alta_trabajo_autonomo)
- [Social Security magazine: how to register as an autónomo, step by step](https://revista.seg-social.es/-/guia-para-darte-de-alta-en-la-seguridad-social-como-trabajador-autonomo)
- [Real Decreto-ley 13/2022](https://www.boe.es/buscar/doc.php?id=BOE-A-2022-12482)
- [Import@ss: contact](https://portal.seg-social.gob.es/wps/portal/importass/importass/contacto)

Next step: [Understand your monthly fee](https://autonomo.eus/steps/monthly-fee.md)

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Free, independent information. Not an official government website or a gestoría. General information, not legal, immigration or tax advice. Confirm current requirements with the authority before you act. Report a mistake: a@halawa.io. Source: Autónomo.eus (https://autonomo.eus).