What is the digital certificate?
A digital certificate (Certificado Electrónico de Ciudadano) is a secure digital ID that proves who you are when dealing with Spanish public administration online. It’s issued by the Fábrica Nacional de Moneda y Timbre (FNMT) and lets you log in, sign documents, submit tax forms, and access official records without having to go to an office.
You install the certificate on your computer or browser, and once it’s set up, it works across a wide range of platforms: AEAT (Hacienda), Seguridad Social, DGT, SEPE, and most regional and local government websites. It’s one of the most widely accepted ways to identify yourself online in Spain.
What is Cl@ve?
Cl@ve is another way to access public services online in Spain without needing to install a certificate. It comes in two main forms:
-
Cl@ve PIN is a temporary code you get via SMS or the Cl@ve app. It’s quick and works well for occasional use.
-
Cl@ve Permanente is a username/password system with added security, more suited for regular use.
Cl@ve works with most national admin sites (AEAT, SEPE, Seguridad Social), and is easier to set up than a digital certificate especially if you don’t have access to a Spanish computer or need to log in from different devices.
What is idCAT?
idCAT is the Catalan digital certificate, issued by the Catalan Certification Agency (Consorci AOC). It functions like any other digital certificate, allowing you to securely access government services, sign documents, and submit forms online.
The key difference is that idCAT is only available in Catalonia. It’s specifically issued by the Generalitat de Catalunya and is widely used for accessing regional services such as ATC (Catalan tax agency), Gencat, and local ayuntamientos. It’s also accepted by national systems like AEAT and Seguridad Social.
If you live in Catalonia, idCAT is often the easiest option to get, since many local offices can help you apply for it in person. No other Spanish region currently has an equivalent general-use certificate – the rest of Spain uses national systems like the FNMT certificate or Cl@ve.
