To do so you only need your Passport and go to the Finance office in Ourique.
There you can ask for “Numero Fiscal” or “NIF”. They will give you a form to fill in and give you your fiscal
number in a matter of minutes.
They don’t speak much English, but the people there are quite nice.
It’s very close to the bank and both things can be done on the same trip.
They are open Monday through Friday from 9:00 am to 3:30 pm (it’s better not to go close to
the closing time).
Here is the google maps location.
And here a picture of the place:
Getting a Portuguese Fiscal Nunber does not mean that you are changing your tax residency to
Portugal, so if you are filing taxes in your home Country, this has no effect.