First day at your new company in Porto. The contract is signed, your badge is waiting, and the person from human resources hands you a sticky note: "I still need your NISS." The NISS in Portugal is your social security number, and without it your employer cannot register you properly. The good news is that the process is now done online and free of charge.
Here is who needs it, how to apply, what changes for French, Belgian and Swiss citizens and other Europeans, and the special case of retirees.
What is the NISS in Portugal and who needs it?
The Número de Identificação de Segurança Social is the number that identifies you, uniquely, with the Segurança Social, Portugal's social security institute. The Portuguese receive it automatically with their Cartão de Cidadão. Foreigners have to apply for it.
You need it as soon as you enter the Portuguese social system:
- if you are an employee of a Portuguese company, so that your employer can declare your contract and pay contributions;
- if you work for yourself in Portugal, to register as self-employed and pay contributions;
- if you want to receive Portuguese benefits one day: unemployment, parental leave, sick leave, pension.
In practice it is also used by other administrations, and it complements your NIF, the tax number. The two often go together: our guide to getting your NIF in Portugal shows you how to obtain it.
How do you apply for your NISS in Portugal online?
Until summer 2025, you could submit your application online, but collecting the number had to be done at a counter. Since August 2025, according to the Portuguese government, foreigners can apply for their NISS and obtain their certificate entirely online.
The path, on the Segurança Social portal: the Ajuda menu, the Número de Identificação de Segurança Social (NISS) section, then Pedir o NISS. The form is for foreign citizens and for Portuguese citizens who are not required to hold a Portuguese identity card. You attach your scanned documents.
The new element is biometrics. Before you start, you authorise the Segurança Social to collect data such as an image of your face or your fingerprints, to check that the person collecting the certificate is the one who applied. According to the text of the form, this data is used only for that purpose and is then deleted.
You then track the status of your application online. If you go through the traditional route, a registered letter tells you where to collect your number, on presentation of a valid ID document. Appointments are booked on the SIGA platform, in the SigaApp or by phone (210 548 888 or 300 088 888, working days from 9 am to 6 pm).
Another option if you already live in Portugal: a public service lets foreigners, including EU citizens, apply for the NIF, the NISS and the SNS utente number in one go. The official page, updated in September 2026, specifies that it is offered only at twelve Espaços Cidadão.
Which documents do EU, EEA and Swiss citizens need?
For citizens of the EU, the EEA and Switzerland, the official gov.pt guide provides for one of these documents, valid:
- the identity card of your home country;
- your passport;
- or your residence card.
A simple copy is enough, whether you apply yourself or a legal representative does it for you. The same guide mentions, for foreigners in general, proof of your professional situation and proof that you have applied for a residence permit, without saying whether this also applies to Europeans. To be safe, keep your employment contract or your declaration of activity to hand, as well as your certificado de registo if you already have it: it is requested from the town hall after three months of residence.
Good news for the Swiss: there is no separate regime here. Switzerland applies the European social security coordination rules with the EU, and the official guide groups Swiss citizens with EU and EEA citizens for the list of documents.
Can your employer apply for the NISS for you?
Yes, and it is common. The employer can apply in your name, provided it presents an original power of attorney or form PA-12, with the ID document of its representative. In any case, it must declare your employment relationship on Segurança Social Direta, its online area.
This route has an advantage: it avoids back-and-forth. It also has a drawback: you depend on how responsive the HR department is. If your start date is approaching and nothing is happening, apply for your NISS yourself online.
Self-employed, remote worker, posted worker: which case is yours?
This is where situations get complicated, and where the NISS in Portugal is only the first piece of the puzzle.
You are self-employed in Portugal. You need a NISS to register as a trabalhador independente and pay your contributions. The calculation rules and the exemptions when you start out depend on your situation: have them checked by an accountant before you declare your activity.
You are posted by your employer. If your employer in France, Belgium or another EU country sends you to Portugal temporarily, you stay covered by the social security of your home country. Your employer requests a portable document A1, valid for up to 24 months, and you do not pay contributions in Portugal during that time.
You work remotely for a foreign employer. This is the grey area par excellence: depending on the share of your work done in Portugal and the agreements between the countries, you may fall under one system or the other. Do not guess: get your situation confirmed in writing. Our article on working remotely from Portugal covers the most common cases.
Retired in Portugal: do you need a NISS or the S1 form?
If you are moving from France and receive only a French pension, you do not enter the Portuguese contribution system. According to Cleiss, you ask your basic pension fund (the CNAV for the general scheme) for the S1 document, preferably before you leave. This form certifies that you remain covered by France for healthcare, and allows you to be treated in Portugal on Portuguese terms.
On the Portuguese side, ACSS, the central health administration, states that the S1 is handed in at the district centre of the Segurança Social for your area of residence, which registers it and tells you which health centre to register with. You have no contributions to pay in Portugal; however, a health contribution may still be deducted from your French pension, depending on your tax situation.
The same principle applies to a Belgian or Swiss retiree whose pension comes only from their home country: it is the body paying the pension that issues the S1. Check with it before you leave. What comes next, on the healthcare side, is explained in our guide to the utente number and the SNS.
How much does the NISS cost and how long does it take?
The application is free, like the one for the NIF. The gov.pt guide gives no official timeframe; online, it all depends on how complete your file is and on the identity check. At a counter, add the time it takes to get an appointment.
The most useful advice remains simple: apply for your NISS as soon as your plans to work in Portugal take shape, without waiting for the first day. A number that arrives late means a first salary that gets complicated.
Once you have the number, create your access to Segurança Social Direta, the personal online area. That is where you check that your employer is declaring your salary properly and where you consult your declarations. You also enter the bank account that will receive any benefits, and later you can request your European Health Insurance Card there for stays outside Portugal. Finally, keep a copy of your NISS certificate on your phone: HR departments and some administrations will ask for it without warning.
If you are still looking for your future job, our guide to working in Portugal as a foreigner gives you concrete leads.