Also on tax returns or social security statements. • https://www.oecd.org/content/dam/oecd/en/topics/policy-issue-focus/aeoi/poland-tin.pdf • www.gov.pl/finanse Portugal For tax purposes: Número de Identificação Fiscal (NIF) (also referred to as “Número de Contribuinte”) Digits: The NIF is composed of nine sequential digits Format: 123456789 You can find your Número de Identificação Fiscal (NIF) on your Portuguese Citizen Card, on your NIF registration document, or by logging into the Portal das