AEAT (Spanish Tax Agency)

Its online filing portal is the Sede electrónica of the Agencia Tributaria. There you file returns, pay or set up direct debit for taxes, check your tax data and receive notifications. To log in you need a digital certificate, Cl@ve or, for some procedures, a reference number.

If you are an autónomo or an SL, the AEAT assigns your NIF, receives your census declaration and checks that you file VAT and withholdings or advance payments every quarter. An SL must deal with it electronically, and notifications reach its enabled electronic address.

The typical mistake is not checking notifications. A request you never open is treated as served once the period set by law passes, and the time to reply starts running even if you have not read it. Log in to the Sede regularly or turn on email alerts.

Do not confuse the AEAT with the TGSS, which runs social security, or with regional and foral tax offices, which manage other taxes. kontora does not replace the AEAT: it leaves your modelos prepared box by box, with deadline reminders, and sends them to the AEAT with your digital certificate when you press "File" (303, 130, 111, 115 and 123 by direct filing; 349, 347, 190, 180 and 193 through TGVI); the rest you file in the Sede.

Guides that use this term

• Verifactu postponed: when it comes into force in 2027, which law sets the dates and what to do in the meantime
• What is Verifactu and does it affect you?
• Digital certificate and Cl@ve for foreign autónomos in Spain: how to get them with an NIE and what each one lets you do
• Choosing accounting software as an autónomo in Spain: Verifactu, the free AEAT app and eight criteria to get it right
• Deferring or splitting a tax payment to Hacienda in Spain: how to apply, what can be deferred and what it costs

Related terms

• Autónomo: An autónomo is a self-employed individual who works independently in Spain and bears the financial risk of their own business.
• NIF: The NIF is the tax identification number used to identify you or your company before the Spanish tax authorities for any fiscal procedure.
• TGSS: The TGSS is the body that manages registration, deregistration, and collection of social security contributions in Spain, including the monthly quota paid by self-employed workers.
• Sede electrónica: A sede electrónica is the official online portal where you file returns, check notifications, and complete procedures with a public body such as the tax agency.
• Cl@ve: Cl@ve is the electronic identification system used by Spanish public administrations, allowing access to online procedures without needing a digital certificate.

Full glossary