The three numbers at a glance
| NIF | NISS | Número de utente (SNS) | |
|---|---|---|---|
| Issued by | Autoridade Tributária (Finanças) | Instituto da Segurança Social | Serviço Nacional de Saúde (health centre / ACSS) |
| What for | taxes, contracts, bank, lease, car, invoices | employment, contributions, benefits, pensions | public health care, prescriptions, SNS 24 |
| When you need it | first — before the visa file | at the first job or self-employed activity | when you register at the health centre |
| Who can request | you, or a proxy with power of attorney | you, a legal representative, or the employer that hires you | you, at the health centre |
| Requirement | passport + foreign address (no residence needed) | identity + NIF; residence document or the employer’s contract | residence permit (or EU registration) + NIF + address |
| Cost | free | free | free |
Portuguese citizens receive all three with their Cartão de Cidadão; foreigners collect them one by one.
- NIF first — by proxy from abroad, no travel
- NISS online — the employer can request it once the contract is signed and reported
- SNS number at the health centre of your fiscal address, with the residence permit
- 15 days to appoint a tax representative when a non-EU resident acquires a tax obligation
NIF — the tax number
Free, nine digits, for life. Requested on the Finanças e-balcão by a proxy (a representante legal with a power of attorney — no notarised signature when given to a lawyer or solicitador), or in person by appointment with passport and proof of foreign address. Issued as non-resident; changed to resident when you register a Portuguese address. A tax representative is not needed to obtain the number; a non-EU resident must appoint one — or join e-notifications — within 15 days of acquiring a tax obligation (property, car, job, activity), and must appoint a VAT representative before starting a self-employed activity. Full detail: how to get a NIF.
NISS — the social security number
The Número de Identificação da Segurança Social is requested online through Segurança Social’s service, by the foreign citizen, by a legal representative on their behalf, or by the employer that is hiring — in which case the employer must first sign the contract and report the employment on Segurança Social Direta. Documents: identity, NIF, and the residence document or the employment contract. Once you hold it, the NISS is the key to Segurança Social Direta, where contributions, sick leave, parental leave and, later, the pension are managed. Self-employed workers register their activity with it (21,4 % contributions after the first-year exemption); employees are enrolled by the employer (11 % employee, 23,75 % employer).
SNS number — the health user number
The número nacional de utente is issued when you register at the health centre (centro de saúde) of your area, which requires Portuguese nationality or a residence permit (EU citizens use the registration certificate) plus the NIF and proof of address. It gives access to a family doctor — subject to availability — to prescriptions, to SNS 24 and to public hospitals under the SNS rules; user fees (taxas moderadoras) are now charged only for hospital emergency visits without prior referral by the SNS (DL n.º 37/2022), with exemptions for children, pregnant women, low incomes and other listed cases. Before the permit exists, care is available privately or through your travel insurance; the health insurance page explains the private options most newcomers keep alongside the SNS.
The order matters. Banks refuse an account without a NIF; AIMA wants the account; the health centre wants the permit; the employer wants the NISS on day one. Access Portugal's set-up service obtains the NIF before the visa appointment, requests the NISS as soon as the contract or the permit exists, and books the health-centre registration the week the card arrives.
Changing details
Address changes are made at Finanças (portal or e-balcão), at Segurança Social Direta and at the health centre; a change of name after marriage or naturalisation is updated at all three with the new document. A NIF is never reissued; a lost NISS card is simply reprinted from Segurança Social Direta.
Questions
Can I get a NISS before I have a job?
Yes: a foreign citizen with a residence document can request it online; without a job it is used to register as self-employed or to access benefits later.
I am an EU citizen. Do I need the residence certificate for the health centre?
Yes — the registration certificate from the town hall (after three months) is your residence document; before that, the European Health Insurance Card covers necessary care.
Is the SNS number the same as the health insurance card?
No. The SNS number is the public system's identifier; private insurers issue their own cards. Both can coexist.
Sources and official references
- Autoridade Tributária — NIF for foreign citizens (leaflet): e-balcão via proxy, appointment, tax representative within 15 days — checked 18.9.2026
- gov.pt — Pedir o NISS: online request by the foreign citizen, a legal representative or the hiring employer (updated 3.9.2026) — checked 18.9.2026
- gov.pt — Inscrever-se no centro de saúde: residence permit required, user number issued at registration (updated 12.5.2026) — checked 18.9.2026
- ERS — SNS user fees FAQ: charged only for unreferred hospital emergencies (DL n.º 113/2011, DL n.º 37/2022); exemptions — checked 18.9.2026
- gov.pt — first Cartão de Cidadão: NIF, NISS and SNS number assigned together for Portuguese citizens — checked 18.9.2026