When you get a NIF through our services, we will request a password from the Portuguese tax office on your behalf. The Portuguese tax office will mail us a physical copy of your password and we will forward that to you.a
You will use this password to get access to their online portal called "Portal das Finanças". Portal das Finanças is where you will interact with the Portuguese tax office.
The first thing you should do after receiving your password is to log in and update your password to something only you know.