The NIF, often known as Contribuinte or the Number of Tax Identification, is the fundamental requirement for engaging in economic activities within Portugal. It holds significance for both residents and non-residents, serving as the initial and essential step. Whether you intend to establish a bank account, engage in real estate transactions, obtain a residence permit, or contract an internet service provider, the NIF is mandatory. Consequently, if you are contemplating a relocation to Portugal, planning to conduct business operations, or even considering an extended stay, registering for an NIF should be regarded as a top priority.