Read the key-information summary
Before signing, read the prospecto de informações essenciais, which must explain how to consult the fees that can be charged.
Check the annual fee and any waiver
Note the anuidade, whether any exemption is temporary, and what the waiver conditions are. The issuer must warn you a month before it starts charging after an exemption.
Choose your due date
You must be offered at least three due dates, at least seven days apart. Pick one that suits your pay date.
Automate payment
If the issuer holds your account, ask for bill payment by account debit or recurring payment.
Check every bill
The bill must identify each fee charged. Question anything you didn't agree to with the issuer's service channel, then the ouvidoria.