A certificate or Cl@ve for submission
Submitting the self-assessment on the Tax Agency site is done with a certificate or with Cl@ve, depending on the procedure. Generating a file in Factura Fácil is an earlier step, and it is not that submission.
What the site asks for
To file modelo 303 or modelo 130 on the site you identify yourself with an electronic certificate or with Cl@ve, when the procedure allows it. Without that access the submission is not completed. Having the figures calculated does not replace identification.
- Site: certificate or Cl@ve.
- The calculation does not identify you to the Tax Agency.
- Importing a file does not leave the form submitted.
The file can be generated beforehand
In the app you can generate the BOE import file for modelo 303 and modelo 130, as ISO-8859-1 text, without that step being the filing. Importing the file into the form does not submit the self-assessment. You confirm the submission on the site, or your gestoría does.
Common questions
Can I leave modelo 303 filed without a certificate?
No. Filing on the site needs a certificate or Cl@ve. You can generate the file in the app, and importing it does not submit the form.
Is importing the BOE file the same as filing?
No. Import loads the data into the form. Filing is the submission, on the Tax Agency site.
Official sources
Informational text reviewed on 26 September 2026. It is not tax advice and does not replace the Spanish Tax Agency or your accountant. Deadlines, rates, and forms can change.