NIF and NISS for foreigners in Portugal: how to get them
Moving to Portugal to live or work? In the first weeks you will need two numbers: the NIF, your tax number, and the NISS, your Social Security number. This guide explains what each one is for, how to get them, and how tax residency changes what you pay.
NIF and NISS at a glance
| NIF | NISS | |
|---|---|---|
| What it is | Tax identification number (9 digits) | Social Security number (11 digits) |
| Issued by | Tax and Customs Authority (Finanças) | Social Security Institute |
| Used for | Taxes, contracts, bank account, renting, invoices | Working, contributions, social benefits |
| Where to apply | Tax office, or online via a representative (e-balcão) | Online form, Social Security counters, or when registering as self-employed |
| When you need it | Before almost anything else | Before you start work |
What the NIF is for
The NIF (número de identificação fiscal) is your number with the Portuguese tax authority. You need it to open a Portuguese bank account, sign a lease or an employment contract, buy a home or a car, set up electricity, water, internet and phone contracts, and put on receipts so your expenses count towards IRS deductions. Having a NIF does not make you tax resident and does not by itself mean you owe tax — it is just an identifier.
How to get a NIF
In person
Go to a tax office (Serviço de Finanças), including the Finanças desks in Lojas do Cidadão, with your passport or EU identity card and proof of address. If the address you give is abroad, the NIF is issued as a non-resident NIF.
Remotely, through e-balcão
If you are still abroad, a representative (a lawyer, solicitor or someone you trust) can apply for you through e-balcão on the Portal das Finanças, with a scan of your ID and a power of attorney. The signature on the power of attorney must be certified, unless it is granted to a lawyer or solicitor.
Do I need a tax representative?
According to the tax authority (Ofício-Circulado 90054/2022), people living outside the EU/EEA do not need to appoint a tax representative just to obtain a NIF. The obligation arises once you have a tax relationship with Portugal — for example, owning property or a car registered in Portugal, signing an employment contract here or starting self-employment. You then have 15 days to appoint one (or must do so when registering self-employment). Residents of other EU/EEA countries do not need one.
Once you live in Portugal
Update your tax address to your Portuguese address. The tax office may ask for proof of residence, such as a residence permit or an EU citizen registration certificate. Also request your Portal das Finanças password, which is posted to your registered address: you need it for your IRS return, the e-fatura invoice system and rent receipts.
What the NISS is for
The NISS (número de identificação de segurança social) identifies you in the Social Security system. Your employer cannot register you without it, and it is how your 11% contributions are recorded — the basis for sick pay, parental, unemployment and pension rights later on. It also gives you access to Segurança Social Direta, the online portal with your contribution record.
How to get a NISS
- Online form: on the Social Security portal, under "Sou cidadão", fill in the NISS request and attach a scan of your ID and proof of the reason (for example, a job offer or contract). You then receive instructions by email and, according to Social Security's guidance, collect the number in person with your ID.
- NISS na Hora: foreign citizens about to start work (as an employee, domestic worker or self-employed) can get the number on the spot at a Social Security counter.
- Through your employer: the employer must report your hiring to Social Security before you start. Many employers also handle the NISS request — ask HR.
- Self-employed: when you register your activity with the tax office, the information is passed to Social Security, which registers you.
Some Espaço Cidadão offices also let foreign citizens with regular status request their NIF, NISS and national health service (SNS) number in a single application. Check gov.pt for the locations.
Tax residency: the 183-day rule
A NIF does not decide where you pay tax. You are Portuguese tax resident if, in any 12-month period starting or ending in the year, you spend more than 183 days in Portugal (consecutive or not), or if, having spent fewer, you have a home here in conditions suggesting you intend to keep it as your habitual residence (art. 16.º of the IRS Code). In the year you arrive or leave, you can be resident for only part of the year.
It matters a lot. Residents pay IRS on worldwide income at progressive rates, with deductions and refunds. Non-residents pay only on Portuguese-source income, generally a flat 25% on salaries. See Portugal tax for foreigners for non-resident rules, IFICI and the returning emigrants' scheme.
Worked example: €2,500 gross a month
Employment contract in Lisbon, single, no dependants, base salary €2,500 in 2026. Figures from our net salary calculator (excluding meal allowance):
| Status | IRS withheld | Social Security | Monthly net |
|---|---|---|---|
| Resident | €471.34 | €275.00 | €1,753.66 |
| IFICI (20%) | €500.00 | €275.00 | €1,725.00 |
| Non-resident (25%) | €625.00 | €275.00 | €1,600.00 |
For a resident, withholding is only an advance settled in the annual return; for a non-resident, the 25% is final. IFICI — the regime that replaced the old non-habitual resident (NHR) scheme — covers qualifying professions and activities, and its flat 20% becomes more attractive at higher salaries. More on take-home pay in the net salary guide.
Common mistakes
- Keeping a foreign address after moving. You stay a non-resident on file and your employer withholds 25%.
- Starting work without a NISS. Contributions may not be linked to you, costing you contribution history.
- Forgetting the tax representative when, living outside the EU, you buy property or a car in Portugal.
- Never activating your Portal das Finanças password. Without it you cannot file IRS or check invoices.
FAQ
Can I get a NIF before arriving?
Yes, through a representative using e-balcão or at a tax office. It stays a non-resident NIF until you update your address.
Is the NISS the same as the health service number?
No. The SNS user number is for the national health service and is requested at your local health centre.
Do the numbers change if I change job or address?
No. Both are for life; you only update your address and contact details.
How long does it take?
An in-person NIF is usually issued during the appointment. A NISS via the online form takes a few days; NISS na Hora is immediate.
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