Informe histórico de bases de cotización (TGSS)

What you need to have to hand

1. DNI/NIE and your NAF/NUSS.
2. Cl@ve (PIN or Permanente), Certificado digital or DNIe. If not, Vía SMS with your mobile registered.
3. Mobile with signal to receive SMS and an email if you want to save the file in the cloud.
4. If it's for someone else, an apoderamiento registered in the Seguridad Social or a signed authorisation plus DNI copies for the office.

Documentation

• Identification: DNI/NIE (or passport + NUSS where applicable).
• Access method: Cl@ve, Certificado/DNIe or Vía SMS (requires NAF, DNI and date of birth).
• Cita previa if you go to a TGSS office.
• Authorisation/apoderamiento if you act for a third party.

Step by step

1. Go to importass.seg-social.es and open Informes y certificados > Informe de bases de cotización.
2. Identify yourself with Cl@ve, Certificado/DNIe or Vía SMS. If the SMS doesn't arrive, update your mobile in Import@ss (Datos personales) and try again.
3. Choose the period (years) and regime. If you had multiple jobs/regimes, select everything relevant.
4. Click Generar and download the PDF with CSV. Check it includes all the bases you need.
5. If you get an error or lack access credentials, book a cita at importass.seg-social.es/citas and request the Informe de bases de cotización at the counter.
6. At the office, show your DNI and they will print it. Check before you leave that it includes the years you asked for.

Time-saving tips

• Chrome/Firefox usually work better for Import@ss. On mobile, Safari sometimes breaks Cl@ve login.
• If you need it for SEPE or a bank, request several full years at once to avoid repeat logins.
• If you use Vía SMS, have your NAF ready. You can find it on payslips, your vida laboral or in Import@ss (Datos personales).
• The PDF has a CSV. Keep the original file, don't edit or re-scan it: that way anyone can verify it.

Common mistakes to avoid

1. Confusing vida laboral with bases: vida laboral doesn't include amounts. They'll reject it.
2. Phone not registered: without a phone on file at Seguridad Social, Vía SMS won't work. Update it first.
3. Treating recent months as final: the latest months can change. Don't finalise calculations until they stabilise.
4. Pluriempleo: don't sum blindly. There's a maximum contribution base and TGSS adjusts it; the report shows each contract separately.
5. Requesting only the last year when they asked for 24 months: check the requirement and download 2–3 years at once.