Metro Manila · International Credit Cards
International Credit Cards are good to withdraw money and to use in upper-class hotels and restaurants. For everything else, you should carry cash.
The acceptance of international credit cards has been on the decrease since some years. Even some supermarkets in large malls do not accept international credit cards anymore. The same goes for some online booking systems for airlines and other websites. It is recommended to always carry cash instead of an international credit card (if you don't know for sure that the place you go to accepts your card), and to have at least two different credit cards issued for the purpose of online shopping.
If you are planning to visit the Philippine countryside, your credit cards will likely be of no use especially if you are going to relatively remote areas. When it comes to going around the Philippines, it is always best to have cash with you.