Comparative law notes
In Brazil, the identification number that is used by the state for tax and other identification purposes with respect to individuals is the Cadastro de Pessoas Físicas (CPF).
There are multiple definitions - click on the translation that matches your context.
Cadastro de Pessoas Físicas (CPF) means:
substantivo próprio
partial
noun
In Brazil, the identification number that is used by the state for tax and other identification purposes with respect to individuals is the Cadastro de Pessoas Físicas (CPF).
(UK) a number unique for each person, used to track benefits, taxes and for other identification purposes
Your National Insurance number can then be used in the future to calculate what tax you are liable to pay.