For Catholic weddings in Portugal you will require a formal letter from your parish priest
granting permission
for the wedding to be performed in your chosen Portuguese church.
Your priest should also secure a letter from the Bishop of the parish
stating the same as above and this letter should also be written on letterhead. The letter from the priest must also state that you have fulfilled all PRE CANA procedures, and should include the certificate (if a certificate was done) showing that you attended the premarital classes.
The original prenuptial inquiry form
has to be issued by your parish and be on formal church letterhead of your Parish. The prenuptial inquiry form is not just the certificate but rather a type of signed questionnaire with church seals/signatures. This document must be stamped by the local Bishop's office
(NOT just your priest).
You will need to have all certificates of baptism, first communion and confirmation
must be sent together with the Prenuptial inquiry form and letters, these must also be stamped by the local Bishop's office.
All the documents mentioned must have been sealed or stamped by the Bishop's parish office and must be translated into Portuguese.