A:Answer Since this is an unlocked phone should work on all GSM internationally. ATT compatible has nothing to do international GSM. Only means will work on ATT in US.
I checked band widths (frequencies) and should have no problem in the Philippines. Personal asking the question should check with local Philippine carries and confirm band widths they are using. My J7 works in most areas in Southeast asia including Viet, Thailand, KL, Hongkong and will probably work in Philippines as well, Just haven't
visited Manila in several years. Think you Mom would like this phone. Easy to use.