If I have a Pass do I also have to validate it?

Except for the Green Rail Pass, you must always validate your Pass before each journey, regardless of the type of card you have.

With the Green Rail Pass, you can travel on urban trains on routes outside the metropolitan area. However, you must present proof of purchase to the ticket inspector on the train transit when they check your ticket.
 

Except for the Green Rail Pass, in the Lisbon and Porto metropolitan areas, you must always validate your Pass before each journey.

Validation is compulsory at stations where there are validators and controlled access channels are in use.

If you have a Green Rail Pass, you must present proof of purchase to the ticket inspector when they check your ticket.