NISS Portugal — Your Social Security Number

The NISS (Número de Identificação de Segurança Social) is your Portuguese social security number. You need it if you are going to work in Portugal — as an employee, freelancer, or self-employed. It is also required for accessing healthcare through the SNS (national health system) and for applying for social benefits.

Who needs a NISS?

Anyone who works or plans to work in Portugal. If you are a retiree or digital nomad not working for a Portuguese entity, you may not need it immediately — but it is useful to have for healthcare access.

Step-by-step

1. Get your NIF first — you cannot apply for NISS without it
2. Locate your nearest Segurança Social office or Loja do Cidadão
3. Book an appointment if possible (segurancasocial.pt or by phone)
4. Bring: valid ID, your NIF, proof of address in Portugal, and proof of employment or self-employment activity (contract, or declaration of activity from Finanças for freelancers)
5. Complete the registration form at the counter
6. Receive your NISS — usually issued on the spot or within a few days

For freelancers (recibos verdes)

If you are opening an activity as a freelancer (opening “actividade”), you register at Finanças first, then go to Segurança Social with the Finanças declaration to get your NISS.