Form 121Skip information index
Online filing of Form 121
Identify yourself with digital signature (electronic DNI or certificate) or using the Cl@ve PIN access system (only natural persons).If the taxpayer does not have an electronic certificate, the person filing must be authorised to file returns on behalf of third parties, either by being registered as a social partner or by being authorised to do so.
Descendants or relatives with disabilities must have a tax identification number.One notification per person with a disability or per large family entitled to the deduction must be submitted.
Once you have completed the form, click on "Validate";if the validation is correct and there are no errors, click on the "Sign and Send" button.
Check "OK" and click "Sign and Send".
If everything is correct, you will get the response screen stating "Your submission has been successfully submitted" with the link "View printable format" which allows you to download the PDF with the submission information.
If you do not have electronic identification you can use the pre-declaration form to fill it in and obtain the PDF to present it in person at the Administration.