If you are new to Portugal, the paperwork gets easier once the initials stop looking interchangeable. Here are the ones you are most likely to meet, with the official starting point for each.
NIF: tax number
NIF is the Número de Identificação Fiscal, also called the número de contribuinte. It is used for tax matters and many everyday transactions, including contracts and bank accounts. The official NIF application page sets out who can request one and how.
NISS: Social Security number
NISS is the Número de Identificação da Segurança Social. It identifies you in Portugal’s Social Security system. Foreign residents can check the current eligibility and document list on the government’s NISS application page; requirements depend on your circumstances.
SNS: public health service
SNS means Serviço Nacional de Saúde, Portugal’s national health service. A número de utente is the user number used in the public health system. Foreign nationals with an address in Portugal can currently request a NIF, NISS and SNS user number together at participating Espaços Cidadão; check the combined service page for eligibility and locations.
SNS 24 is the health advice and triage line. Call 112 for an emergency. For non-emergency health-service information, use the current SNS 24 site.
AIMA and the old SEF
AIMA is the Agência para a Integração, Migrações e Asilo. It is the current agency name you will see on many migration and residence pages. SEF was the former Serviço de Estrangeiros e Fronteiras; it is still mentioned in older guides, so check the date and follow the current official instructions at AIMA.
CRUE: EU citizen registration
CRUE is the Certificado de Registo de Cidadão da União Europeia. EU, EEA and Swiss citizens staying in Portugal for more than three months need to consult the current registration rules. AIMA says the application is made at the Câmara Municipal for the place of residence, within 30 days after the first three months in Portugal. See AIMA’s CRUE guidance before booking or gathering documents.
AT, IRS and IVA
AT is the Autoridade Tributária e Aduaneira, Portugal’s tax and customs authority. You will also hear people call it Finanças, after the tax offices and online portal. IRS is personal income tax; IVA is value-added tax (VAT). For tax status, filing dates and forms, start at the official Portal das Finanças, not an old expat checklist.
IMT, Câmara and Junta
IMT is the Instituto da Mobilidade e dos Transportes. Its remit includes driving licences and vehicle matters; rules for exchanging a foreign licence depend on where it was issued and your situation. Use the current government licence-exchange guide before driving or applying.
Câmara usually means the Câmara Municipal, or municipality. Junta is short for Junta de Freguesia, the parish council. Which office handles a request depends on the service, so check the relevant municipality’s own page rather than assuming the Junta and Câmara are interchangeable.
For anything involving residence, taxes, health access, work or a driving licence, use the linked official page and check when it was updated. A familiar acronym is useful; it does not tell you which rule applies to you.
