NIF vs NISS vs SNS

Quick comparison

Sources: Autoridade Tributária e Aduaneira (info.portaldasfinancas.gov.pt) · Segurança Social (seg-social.pt) · Serviço Nacional de Saúde (sns.gov.pt). Government fees are correct as of 2026.

The NIF (Número de Identificação Fiscal, also called Número de Contribuinte) is a 9-digit tax identification number issued by the Portuguese Tax and Customs Authority (Autoridade Tributária e Aduaneira, commonly called Finanças). It is required for any financial transaction in Portugal — opening a bank account, signing a rental contract, buying property, paying utility bills, or simply receiving a salary.

When you actually need a NIF

• Buying or renting property in Portugal.
• Opening a Portuguese bank account.
• Applying for any Portuguese visa (D7, D8 Digital Nomad, Golden Visa, work visa, student visa).
• Starting a business or working as a freelancer (precedes NISS).
• Receiving an inheritance, signing power of attorney, or any notary act.

How to apply

You have three options. (1) Visit a Finanças office in Portugal in person — free if you are a tax resident, but there are queues. (2) For non-residents, Finanças requires a tax representative resident in Portugal who handles correspondence — most banks and law firms charge €100-300/year for this. (3) Use a service like FastNIF, where a registered Portuguese law firm acts as your tax representative for the first year and submits your application electronically. About 10 business days, no need to be in Portugal, €99.90 one-time.

The NISS (Número de Identificação da Segurança Social) is an 11-digit number issued by the Instituto da Segurança Social. It tracks your social security contributions and entitles you to unemployment, maternity/paternity, sickness, and pension benefits. Unlike NIF, NISS does not get used for everyday transactions — it surfaces specifically when employment, self-employment, or formal residence comes into play.

When you actually need a NISS

• Signing an employment contract in Portugal.
• Registering as self-employed (abertura de atividade).
• Setting up a Portuguese company.
• Most residence permit applications (D7 retiree, D8 digital nomad, work visa).
• CPLP mobility agreement applicants (Brazil, Cape Verde, etc.).

NISS used to be requested in person at a Segurança Social office, but most cases now go through the employer or via Power of Attorney. FastNIF generates an SNS-specific PoA, collects your supporting documents (passport, NIF, employment proof or self-employment declaration, visa or residence permit), and submits the application electronically. Approximately 1 week from document approval to NISS delivery.

The Número de Utente do SNS is the user number for Portugal's National Health Service. With it, you can register with a family doctor (médico de família) at your local Centro de Saúde, get prescriptions at public-system prices, attend public hospitals at subsidized rates, and use the SNS24 helpline. The number itself is free — but the application paperwork is in Portuguese, and the rules differ between health centers, especially for foreigners without an EU residence permit.

Why getting SNS is harder than NIF or NISS

• You need a verified Portuguese address — your application goes to the health center that covers your parish (freguesia).
• Each parish has its own health center with its own clerk, and rules vary — some accept email submissions, some require in-person visits, some refuse foreigners without certain visa types.
• The required documents go beyond NIF/NISS: passport, NIF proof, address proof, visa or residence permit, AND your father's and mother's full names — required by the SNS for record-matching.
• Lisbon district has a central email address (lxcentral.inscricoes@arslvt.min-saude.pt) covering several parishes, but other districts must be contacted individually.

FastNIF currently prioritizes Lisbon-area applicants because we have direct experience with the central email and can guarantee submission. For other districts, we still accept applications but recommend contacting our support team via WhatsApp first to confirm whether the local rules will work for you.