NIF, NISS, Chave Móvel Digital and SNS: what to get first in Portugal (2026)

Move to Portugal and you'll hear about four numbers in your first week: NIF, NISS, Chave Móvel Digital and your SNS number. Ask in any expat group which comes first and you'll get five answers.

The short version: NIF first, from abroad. Everything else hangs off your residence status and a Portuguese address. This guide walks through what each one is, what it needs, and the order that saves you repeat trips.

Quick note: this is general information and the rules change often. Check your own case with the office involved (Finanças, Segurança Social, AIMA or your health centre) or with an adviser before you act.

Key takeaways

• Get your NIF before you move. You can do it remotely through a representative, and you'll need it for a bank account, a lease and most visa files.
• The NISS and a fully working SNS registration both depend on your residence status. Plan them for after your AIMA application, not before.
• Without a Portuguese Cartão de Cidadão, you activate the Chave Móvel Digital at a counter, not online. You can use your passport.
• Foreigners with a Portuguese address and a residence application can now ask for NIF, NISS and SNS numbers in one request, but only at 12 Espaços Cidadão so far.
• An SNS number on its own doesn't mean the SNS covers your care. Your NIF, Portuguese address and valid residence permit have to be linked to it.

The four numbers in one table

Here's what each one is, who gives it to you and what you need to have in hand.

The order that works

Think of it in two phases: what you can do from abroad, and what waits until you've applied for residence and have a Portuguese address.

Before you arrive

1. NIF. Any foreigner, resident or not, can ask for one at any time, according to gov.pt. You'll need it to open a bank account and sign a lease, and many visa files expect it.
2. Chave Móvel Digital, if you want a head start. Foreigners can activate it with a passport at a counter, and Autenticação.gov lists Portuguese consular services among the places that do it. If you'd rather wait, you can also create it at the Espaço Cidadão when you ask for your other numbers.

After you've applied for residence and have a Portuguese address

1. NISS and SNS number, together or separately. If you're near one of the 12 Espaços Cidadão running the combined request, ask for your numbers there in one go. If not, file the NISS online and register at your health centre.
2. Update your NIF address. Once you become tax resident, the Tax Authority's own leaflet says you have 60 days to tell them and move your NIF record to your Portuguese address.
3. Complete your SNS record at your health centre. The number alone isn't enough: the SNS only covers your costs once your NIF, Portuguese address and residence permit are linked to it.

NIF: the one you get first

The NIF (Número de Identificação Fiscal) is your tax number. gov.pt describes it as the number you need to buy goods or services, sign contracts or open bank accounts. It stays the same whether you're registered as resident or non-resident.

As a non-EU citizen living abroad, you can apply as a non-resident with your passport. You can file through the Finanças e-balcão (via a legal representative) or in person with an appointment at a Finanças office or Loja do Cidadão.

The tax representative is where people get confused. gov.pt lists a fiscal representative as mandatory for non-EU non-residents. The Tax Authority's leaflet for foreign non-residents adds detail: once you have a tax relationship in Portugal, such as owning property, a car, a work contract or self-employment, you have 15 days to appoint a representative or sign up for electronic notifications. If you're self-employed in Portugal while living outside the EU, you need a VAT representative before you start. Missing a mandatory appointment can mean a fine of €75 to €7,500.

In practice, most people applying from the US appoint a representative at the same time as the NIF, so tax mail has somewhere to land.

Want the full walkthrough? Read our guide to getting a NIF in Portugal.

NISS: your social security number

The NISS (Número de Identificação da Segurança Social) is the number that lets you access your rights and meet your obligations with Segurança Social. If you'll work in Portugal, employed or self-employed, you'll need one. Portuguese citizens get it automatically with their Cartão de Cidadão. Foreigners have to ask, and gov.pt says the request is free and made online.

Option 1: the Segurança Social online form

You fill in the Segurança Social form for foreign citizens and attach scanned documents. For non-EU citizens, the official list has three parts:

• Identification: passport, work visa, and a residence permit or other ID from your home country.
• Proof of a work situation: an employment contract, your self-employment registration with invoices or receipts, a company registration certificate, a contract with a foreign employer for digital nomads, or a document backing voluntary social insurance.
• Proof of residence: your residence permit, or the receipt for your residence application.

Your employer can also apply for you, but only after signing your contract and reporting it to Segurança Social. When the NISS is ready, you get a registered letter at the address you gave, and you pick it up at a Segurança Social counter. gov.pt is blunt that there's no set deadline for Segurança Social to assign it.

Option 2: the combined NIF, NISS and SNS request

Foreigners with a Portuguese address can ask for all three numbers in one go. According to the gov.pt service page, you qualify if you've applied for or already hold a residence permit (among other groups, such as EU citizens and people under international protection). You bring your passport, your residence card or your AIMA application receipt, and proof of address if your document doesn't show it. You authenticate with a Chave Móvel Digital linked to your passport, and if you don't have one yet, you can create it on the spot.

AIMA then reviews the request and emails you the decision. It can be approved in full, approved with only some of the numbers, or rejected.

The catch: gov.pt says it's only available at 12 Espaços Cidadão for now, in the Lisbon, Porto, Braga, Setúbal and Faro districts, with more counters to follow. Check the current list on the service page before you travel. If you don't meet the conditions, you apply for each number separately.

The claim that AIMA hands out the NISS at your appointment

You'll see this a lot in expat groups. Here's what the primary sources say. In March 2025 the Tax Authority announced data sharing between AIMA, Finanças, Segurança Social and the health system, so that people regularising their stay through AIMA get their NIF, NISS and SNS numbers assigned automatically and are registered as residents. The live service built on that is the combined request at an Espaço Cidadão described above.

Some members report getting numbers straight out of their AIMA appointment. We couldn't find an official page that promises this for every appointment, so ask at yours and don't count on it.

Residence card: needed for the NISS or not

Not necessarily the physical card. Both routes accept the receipt for your residence application. What the online form also wants is a work basis. If you're retired or living on passive income, you won't have any of the work documents on that list. In that case the combined request, which asks about residence rather than work, is the one to look at. Confirm with Segurança Social for your situation.

For what the system actually covers, see our guide to Portuguese social security.

Chave Móvel Digital: your government login

The Chave Móvel Digital (CMD) lets you log in to public and private portals and sign digital documents, always with the same PIN. It's free and open to foreigners.

Here's the part people get wrong. Online activation, through Autenticação.gov, the gov.pt app or the Finanças login, needs a Portuguese Cartão de Cidadão. Without one, you activate it at a counter. That covers Espaços Cidadão, Espaços Empresa, criminal records offices and Portuguese consulates, among others.

What you bring as a foreigner:

• Your passport, or
• Your residence title or card, but only if you already have a Portuguese NIF. Some residence certificates don't allow the digital signature feature.
• The phone you want to link to the CMD. Every person needs their own number, children included.

Your CMD is valid for as long as the document you linked it to. If you set it up with your passport and later get a residence card, keep an eye on expiry dates. You can also ask the counter to add your NIF, NISS and SNS numbers to your CMD. Autenticação.gov confirms that a residence title needs a NIF to activate.

SNS número de utente: the health system number

Your número de utente is your registration with the Serviço Nacional de Saúde. For foreigners, gov.pt says it's assigned the first time you go to a public health unit, such as a health centre or hospital. You can also ask for it at any public health unit without needing care that day. To register, you give your name, sex, date of birth, nationality and country of birth. They may ask for your address, phone and email too.

The number alone doesn't mean the SNS pays for your care. For coverage, your record needs your ID document, Portuguese NIF, full Portuguese address and a valid residence permit linked to it. The law does cover some situations without those details.

So the SNS step comes last on purpose. Once your residence permit and address are in place, go back to your health centre and make sure all of that is on file.

Waiting on your residence permit, or want faster access than the public system? Read our guide to health insurance in Portugal.

Common mistakes

• Keeping your NIF on your representative's address after you move. Your NIF record should follow you once you're tax resident. The Tax Authority gives you 60 days to update it, using your residence title or AIMA receipt as proof.
• Filing the NISS online form without a basis. No work document and no residence application means the form is missing what Segurança Social asks for.
• Trying to activate the CMD online with a residence card. Online activation is for Cartão de Cidadão holders. Go to a counter.
• Assuming an SNS number means free care. Coverage depends on the NIF, address and residence permit linked to your record.
• Planning around the one-stop service in a city that doesn't have it. Check the list of 12 counters before you book a trip.
• Forgetting the 15-day rule. Buy property or sign a work contract while you're still a non-resident, and you have 15 days to appoint a tax representative or sign up for electronic notifications.