Moving to Portugal comes with a fair amount of paperwork. Among the first things you will probably hear about are the NIF, NISS and SNS User Number.
Although all three are identification numbers, they serve completely different purposes.
What is a NIF?
The NIF (Número de Identificação Fiscal) is your Portuguese Tax Identification Number.
It is issued by the Portuguese Tax and Customs Authority and is used for matters related to your finances and taxes in Portugal.
You will commonly need a NIF when:
- Opening a Portuguese bank account
- Signing a rental agreement
- Buying or selling property
- Working or becoming self-employed
- Issuing or receiving invoices
- Filing taxes
- Making certain purchases or financial transactions
For anyone planning to live in Portugal, the NIF is usually one of the first numbers to obtain. You may be asked for it in many everyday situations, from signing a mobile phone contract to renting a property.
What is a NISS?
The NISS (Número de Identificação da Segurança Social) is your Social Security Identification Number.
It identifies you within the Portuguese Social Security system. The NISS is particularly important if you are working in Portugal or are otherwise covered by the Social Security system.
You may need a NISS when:
- Starting a job in Portugal
- Registering as a self-employed worker
- Paying Social Security contributions
- Accessing Social Security benefits
- Managing your Social Security information through Segurança Social Direta
Your employer will also use your NISS when dealing with your employment and Social Security contributions.
What is the SNS User Number?
The SNS User Number (Número de Utente do SNS) identifies you within Portugal’s public healthcare system, the Serviço Nacional de Saúde (SNS).
It is associated with your healthcare registration and allows the Portuguese health system to identify you as a patient.
You may need it when:
- Registering with a health centre
- Accessing healthcare through the SNS
- Making appointments
- Managing your healthcare information
- Accessing certain public healthcare services
If you move to a different area of Portugal, you may also need to update your registration with the health centre corresponding to your new address.
So, what is the difference?
The simplest way to remember the three is to think about what each one is used for.
Your NIF is related to taxes and financial matters.
Your NISS is related to Social Security and employment.
Your SNS User Number is related to public healthcare.
They are completely separate numbers and having one does not automatically mean you have the others.
Do you need all three?
Not necessarily.
The numbers you need will depend on your circumstances in Portugal.
If you are moving to Portugal and renting a home, opening a bank account or dealing with tax-related matters, you will generally need a NIF.
If you are going to work or become self-employed and will be covered by Portuguese Social Security, you will need a NISS.
If you are registering with the Portuguese public healthcare system, you will need an SNS User Number.
For many people who settle in Portugal, having all three is completely normal because they serve different purposes.
Are these numbers the same as your Portuguese ID number?
No. This is another common confusion.
Your NIF, NISS and SNS User Number are not the same as your passport number, residence permit number or Citizen Card number. They identify you for different public services and administrative purposes.
At EasyRelocation, we can help you navigate the administrative side of your move and make settling into Portugal much easier.
Need help with your move to Portugal? Get in touch with our team.


