NIF and NISS: the two numbers you need

NIF: your tax number

The NIF (número de identificação fiscal) is used for everything in Portugal: renting, opening a bank account, buying a phone contract and, of course, invoicing. You can request it:

• at any tax office (Serviço de Finanças) or Loja do Cidadão, with your passport or ID card and proof of address;
• through a lawyer, accountant or service company, if you are not in Portugal yet.

If your address is outside Portugal, you may have to appoint a fiscal representative or sign up for electronic notifications. The rules changed in recent years and depend on where you live, so check the current requirements on gov.pt before you go.

When you move to Portugal, update your address on the tax record. That is what makes the tax authority treat you as a resident.

Portal das Finanças password

Ask for the password on the Portal das Finanças with your NIF. It arrives by post at your registered address within a few days. Without it you cannot register as a freelancer or issue invoices.

NISS: your social security number

Foreign citizens who are legally in Portugal can request a NISS (número de identificação da segurança social) online, with the form "Pedido de NISS – Cidadão Estrangeiro" on the Social Security website, attaching a passport or ID card. Then activate your access to Segurança Social Direta, where you file the quarterly declaration and pay contributions.

Chave Móvel Digital

The Chave Móvel Digital is a digital ID that logs you in to the Portal das Finanças, Segurança Social Direta and most public services with your phone. Once you have a residence permit and Portuguese phone number it is worth setting up.

Then register your activity

With the NIF and password you can open your activity on the Portal das Finanças. See recibos verdes explained.

Official guide: "Como pedir o NIF e o NISS para pessoas estrangeiras em Portugal", gov.pt. Requirements can change; check before you apply.