Download the official Form TA1, to “Apply for Social Security affiliation, Assignment of a Social Security Number, and Data Modification” in PDF format, provided by the Ministry of Labor, Migration and Social Security. 

If you need to register as an employee with Social Security, it is mandatory that you complete and submit Form TA1, which is the application form to register with Social Security. If you have a digital certificate or Cl@ve, you can make the request through the Electronic Office of Social Security.

What is the Form TA1 of Social Security?

The Form TA1 is the application form that you must fill in to proceed with the affiliation with Social Security and get a Social Security number assigned to you if you have not been previously registered. The employer who is going to hire a worker who does not have a Social Security Number must request it since this is the number that identifies the citizen before this Administration.

Here, in the Form TA1 of Social Security, you have to fill in the following data:

Applicant details:


Information related to the application (you must mark an X in the corresponding box):


-Data related to the notifications:


Subsequently, you will be given a receipt for completing the Social Security Affiliation Application, Assignment of a Social Security Number, and Data Modification (Form TA1). The data displayed in this form will be incorporated into the General Affiliation File (“Fichero General de Afiliación”).

Who can request Form TA1?

The Social Security Affiliation Number, as well as registration to the system, may be requested by the following entities/people:


The Application Form TA1 must be addressed to the Provincial Directorate of the General Treasury of Social Security or to the Administration of the province where the company in which you work is registered. Likewise, you can submit it to the tax address of the self-employed worker.

Keep in mind that the request must be made before the employee begins to provide their services to a company. It can be done 60 calendar days prior to the work year.

We hope this information has been useful to you! If you need advice regarding Social Security procedures, you can contact Entre Trámites and we will help you. Contact us through our contact form, or through WhatsApp.

It’s always a good idea to leave your bureaucratic paperwork in the hands of specialists.