If you're from the USA and want to purchase a prepaid Subscriber Identity Module (SIM card) from a Costa Rican cellular provider, you need an UNLOCKED phone from AT&T or T-Mobile. If your phone is uses CDMA (Code Division Multiple Access) such as Sprint, Verizon or MetroPCS, then your phone does not use a SIM card and will NOT accept a pre-paid SIM card from a Costa Rican cellular provider.
