How to apply for NISS in Portugal as an American

If you're planning to work in Portugal, you'll need a NISS (Número de Identificação da Segurança Social). It's Portugal's social security identification number, and it connects you to the country's system for employment, healthcare, and benefits.

Many Americans moving to Portugal get confused about when they need a NISS, how to apply for one, and what documents are required.

Here's everything you need to know about getting your NISS as an American.

We'll also introduce Wise — your international money transfer alternative. Use Wise to send stress-free transfers to over 140 countries - all at the standard mid-market exchange rate.

Learn more 🔎

What is a NISS number in Portugal?

A NISS is your social security identification number in Portugal.

The Portuguese Social Security Institute (Instituto da Segurança Social) issues this number to track your social security contributions, benefits, and employment history.

You need a NISS to work legally in Portugal, whether as an employee or self-employed. Without it, employers can't legally hire you or register you for social security contributions.

The NISS also gives you access to Portugal's National Health Service (SNS), unemployment benefits if you qualify, maternity and paternity leave benefits, sickness benefits, retirement pensions, and family allowances.

Step-by-step process for applying for a NISS number as an American

Applying through your employer

If you already have a job in Portugal, the easiest way to get a NIFF is through your employer.

Portuguese employers are legally required to register their workers with social security, and they know the process. Here's how it works:

1. Provide your employer with the required documents, including your valid passport, NIF number, proof of Portuguese address, signed employment contract, and birth certificate
2. Your employer submits the application online
3. The system processes your application and issues your NISS
4. Your employer receives notification and gives you your NISS number

This is usually a straightforward process, but it can still take up to 3 weeks for everything to get processed and for you to receive your NIFF.¹

Applying at a Social Security office

If you're self-employed, don't have a job yet, or your employer isn't handling the application, you can apply independently at the Social Security office.

Here's how to do this:

1. Locate your nearest Social Security office
2. Check if you need an appointment or if they accommodate walk-ins
3. Gather all required documents, including your valid passport, NIF number, proof of Portuguese address, birth certificate, and proof of intent to work (such as employment contract, self-employment registration, or a written declaration of intent to seek employment)
4. Visit the office with your documents
5. Complete the NIFF application
6. Receive confirmation that your application is being processed
7. Your NISS will be mailed to your Portuguese address within a few weeks to a couple of months¹

As an American (non-EU citizen), you'll also likely need to show your work visa or residence permit.

Applying through a legal representative

If you're not yet in Portugal or prefer professional help, you can authorize a legal representative (lawyer, accountant, or specialized service) to apply for a NISS on your behalf.

Follow these steps:

1. Find a legal representative in Portugal who offers NISS application services
2. Grant them power of attorney (procuração)
3. Send them copies of your passport, NIF, proof of Portuguese address, birth certificate, and any other required documents
4. The representative submits your application using the power of attorney
5. Once issued, they receive your NISS and forward it to you

This approach removes you from the bureaucratic process, but you'll need to cover your legal representative's fee, so there's an extra cost associated with it.

Can you apply for a NISS number from the US?

You can't apply for a NISS from the US on your own, but you may be able to authorize a legal representative in Portugal to do it on your behalf. You would prepare a notarized and apostilled power of attorney in the US and send it to your representative, along with your documents.

However, the process is usually much more straightforward once you're in Portugal and have your NIF and proof of address ready.

Different types of NISS

Portugal doesn't issue different "types" of NISS numbers, but your NISS registration falls into different categories depending on your work status, such as an employed or self-employed worker.

You can switch between categories if your work situation changes. For example, if you start as an employee and later become self-employed, you update your status with Social Security, but your NISS number remains the same.

Processing times for getting a NISS number in Portugal as an American

How fast you receive your NISS number largely depends on which application method you use:¹

• If your employer applies for you, the process typically takes a few days to 3 weeks
• If you apply independently, it'll take longer—expect a few weeks to a couple of months
• If you apply through a legal representative, the timeline is usually similar to applying independently

Overall, it’s not the fastest process.

FAQ

How much does it cost to get a NISS number in Portugal?

Applying for a NISS at a Portuguese Social Security office is free. But if you use a legal representative to apply on your behalf, you'll pay their fee for services.

How long does it take to get a NISS number in Portugal?

If your employer applies for you, you'll typically receive your NISS within a few days to 3 weeks. If you apply independently at a Social Security office or through a legal representative, expect the process to take a few weeks to a couple of months.¹

What is the difference between a NISS and a NIF?

A NIF (Número de Identificação Fiscal) is your tax identification number in Portugal. You need it to file tax returns, apply for a mortgage, open bank accounts, buy property, sign contracts, and more.

A NISS (Número de Identificação da Segurança Social) is your social security number. You use it for employment and social benefits.

You need both numbers to live and work legally in Portugal, but they exist for different purposes.

Can I work without a NISS in Portugal?

No, you can't work legally in Portugal without a NISS. Portuguese law requires all workers, whether employed or self-employed, to be registered with the social security system. Employers can't legally hire you or process payroll without your NISS number.

Applying for a NISS in Portugal isn't always straightforward, but it's definitely doable. You can ask your employer to handle the application, or you can apply independently.

Either way, a NISS number opens the door to legal employment, healthcare access, and social benefits in Portugal.

If you're moving to Portugal for work or planning to settle there long-term, you'll probably be transferring money between the US and Portugal regularly.

Converting USD to EUR for rent, living expenses, or sending money back to the US means going through a currency exchange.

Banks typically add an unfavorable markup on the exchange rate—often 3-5% or more. These costs can add up quickly when you're moving larger amounts or making frequent transfers.

It pays off to research better alternatives for transferring money internationally, such as Wise.

🚀 Get started with Wise

Sources

1. Pearls of Portugal - How to get your Portuguese NISS as a foreigner

Sources checked 03/26/2026