A:AnswerThe phone worked with Walmart's phone service (Straight Talk?). I would confirm with Consumer Cellular first. The Best Buy agent did the checking while we were in the store.
A:AnswerYes, you can add an SD card to expand your memory. As to use in Portugal, I have no idea. It is a very good phone, my wife and I both have one and we are very happy with them.
A:AnswerAn unlocked phone can be purchased and brought to any phone company to activate. A locked phone is company (AT&T, Sprint, Verizon...) specific.
A:AnswerHello Muilisx, thank you for asking! Please follow this link (https://www.samsung.com/us/mobile/phones/all-other-phones/galaxy-j7-16gb--unlocked--sm-j737uzkaxaa/?redir=SM-J737UZKAXAA#specs) to review all the specifications for this device. ^Elizabeth