1. What is a NISS?
The Número de Identificação da Segurança Social links social security rights and duties to an individual. A NIF is a tax number, a NISS is a social security number, and the Número Nacional de Utente identifies a health-service user.
2. Who can apply and why?
- An employee with an employment contract
- A self-employed person registered with Finanças
- A company officer
- A digital nomad employed abroad
- A person eligible for voluntary social insurance
The application must state and document the reason why a NISS is required.
3. Online application
- Open the “Pedido do NISS” form on Portal da Segurança Social.
- Enter identity, nationality, contact and address details.
- Select the reason and upload the relevant work evidence.
- Add the applicable identity and residence/application evidence.
- Track the request online.
- After approval, obtain the certificate online using biometric identity verification.
Since the system announced on 13 August 2025, foreign applicants no longer have to collect every NISS certificate at a counter.
4. Documents
| Status | Example evidence |
|---|---|
| Identity | Valid passport plus the applicable visa, residence document or accepted application receipt listed by the authority |
| Employee | Employment contract |
| Self-employed | Start-of-activity registration and, where applicable, invoices/receipts |
| Company officer | IRN company record or permanent commercial certificate |
| Digital nomad | Contract with the foreign employer |
| Voluntary insurance | Evidence establishing eligibility for SSV |
A NIF field appears in the online form. Always follow the live form’s current document instructions.
5. Employer filing and starting work
An employer may request a NISS for a foreign recruit. The employer must first conclude an employment contract and report the employment relationship through Segurança Social Direta.
6. Cost and processing
The official NISS application is free. The authority does not promise one universal completion time, so a guaranteed “10–15 working days” should not be advertised.
Missing or inconsistent identity, work-purpose or residence evidence may delay the request.
7. After allocation
- Keep the NISS certificate securely.
- Activate Segurança Social Direta access.
- Give the number to your employer.
- If self-employed, check declaration and contribution dates.
- Correct identity errors instead of applying for a duplicate number.
Allocation alone does not necessarily start contributions; timing depends on employment status and social security rules.
8. Common mistakes
- Confusing NISS with NIF or the SNS user number
- Believing a contract cannot be signed without a NISS
- Applying without evidence of the allocation reason
- Repeating outdated “NISS na Hora” advice
- Applying again when a NISS already exists
9. Official sources
Frequently asked questions
Is the NISS application free?
Yes. The official online application is free.
Can a contract be signed without a NISS?
Yes. A NISS does not have to appear in the employment contract.
Can my employer apply?
Yes, after concluding the contract and reporting the employment relationship through SSD.
Is NISS a health number?
No. SNS user registration is separate.
Does NISS grant residence?
No. It is a social security identifier.