Updated on: 11-07-2024

Registration

Allocation of a Portuguese Social Security Identification Number to Foreign Citizens on Time

What is the Social Security Identification Number (NISS)?

The Social Security Identification Number (NISS) is the number that allows a unique, precise and accurate identification of citizens towards the Social Security system, at national level.

Social Security Identification Number application form

The Social Security Identification Number (NISS) is automatically allocated to national citizens when they apply for the Citizen Card.

The request for the allocation of a Social Security Identification Number (NISS) to a foreign citizen or a national citizen who is not required to have a citizen card is submitted by completing the online form available here: Formulário para pedido de Número de Identificação de Segurança Social (Social Security Identification Number application form).

How is the Social Security Identification Number (NISS) allocated to Legal Persons?

The request for the allocation of a Social Security Identification Number to legal persons (registration in the Social Security system) is made automatically to the Social Security Institute whenever the legal persons (companies) are created online.

When the legal persons (companies) are registered at the commercial registry offices, this fact is communicated ex officio, electronically and free of charge by the commercial registry offices to the Social Security Institute.

The legal persons registration is mandatory and it is communicated ex officio through automatic data transmission by the Tax and Customs Authority (AT) to Social Security, on the date of:

the activity beginning communication;
the creation of companies/associations under the special scheme for the immediate creation of companies and associations, the online creation of companies, or the immediate creation of permanent representations of foreign entities;
communication by the registry offices of the employers registered under the commercial scheme and of the employers included in the central registry of companies, in the case of entities not subject to mandatory commercial registration;
admission of the first worker, in the case of natural persons who benefit from the professional activity of third parties, carried out under an employment contract;
the inspection and supervision activities (in the case of entities created without official registration, with workers at their service).

For further information on the allocation of a Social Security Identification Number (NISS) to legal persons, please see the Practical Guide – Registration and Change of Data – Legal Person.

How is the Social Security Identification Number (NISS) allocated to Natural Persons?

NATIONAL CITIZENS WITH A CITIZEN CARD

The Social Security Identification Number (NISS) is automatically allocated to national citizens when they apply for the Citizen Card.

FOREIGN CITIZENS

The request for the allocation of a Social Security Identification Number (NISS) to a foreign citizen or a national citizen who is not required to have a citizen card is made through an online form available on the Social Security Portal; in the Sou Cidadão (I am a Citizen) menu, click on Atribuição de Número de Identificação de Segurança Social (NISS) (Allocation of Social Security Identification Number – NISS) > Formulário para pedido de Número de Identificação de Segurança Social (Social Security Identification Number application form).

Please note: When the application is submitted by the Employer, it is exclusively aimed to the allocation of a Social Security Identification Number to the foreign citizen, being the Employer required to communicate the worker's employment relationship, through the Social Security Online Service (SSD – Segurança Social Direta).

Necessary documents for the NISS application submission

A copy of the civil identification document of the applicant, valid at the time of the application submission, must be submitted to prove his/her identification. The accepted ID documents are the following:

In the case of a national citizen without a citizen card, he/she must submit a valid ID card;
In the case of a foreign citizen from a third country, i.e., countries that are not members of the European Union (EU) or of the European Economic Area (EEA) - Any country not bound to Portugal by an international agreement or convention on the coordination of social security systems:
- Simple copy of the Passport, Work Visa, Residence Permit, Residence Authorization (Temporary/Permanent), whether the application is submitted by the citizen or a legal representative on his/her behalf.

Please note: In accordance with Article 84 of Law no. 23/2007, the residence permit shall replace, for all legal purposes, the ID document, without prejudice to the arrangements provided for by the Treaty of Friendship, Cooperation and Consultation between the Portuguese Republic and the Federative Republic of Brazil, signed in Porto Seguro on 22 April 2000.

Proof of employment status:
- employment contract or;
- copy of the document attesting the self-employment activity beginning and copy of the receipts/invoices or;
- company registration certificate issued by the Institute of Registries and Notary (IRN).
Proof of application for residence regularisation:
- proof of application for a residence permit or;
- proof of application for a residence visa for citizens of the Community of Portuguese Speaking Countries (CPLP) or;
- proof of application for a Residence Permit Certificate for CPLP citizens.

Please note: A foreign citizen who is qualified as a Member of Statutory Body (MOE) of a company identified in the Social Security Information System (SISS), and who is residing abroad, may not be required to submit any supporting documents of residence permit or visa application.

Necessary documents for the NISS application submission by an Employer or Legal Representative

Power of attorney (original document) or form PA-12 (Declaration of Authorization to Third Parties) – in which the foreign citizen authorizes the legal representative to apply for the allocation of a Social Security Identification Number (NISS) on his/her behalf – and the legal representative's identification document (Passport, residence permit or other civil identification document of the country of origin). The NISS document must be collected by the citizen himself/herself (citizen to whom the NISS was allocated).

All the necessary data for the identification of a foreign citizen before the Social Security System must be provided, more specifically the following data included in the Form:

Full name;
Date of Birth;
Gender;
Marital status;
Country of birth;
Place of birth;
Nationality;
Type and number of Civil Identification Document;
Expiry date;
Taxpayer number (if already allocated);
Country of residence;
Address
Address (to be indicated only if the country of residence is ≠ PT);
Mobile phone number
Email
Please attach copy of the identification document;
Please attach copy of the legal representation document (if there is a legal representative)

You may find information on the necessary documents for the examination of the NISS applications and additional information in the Practical Guide – NISS NA HORA – Allocation of a Portuguese Social Security Identification Number to Foreign Citizens, on time.