Using a Cell Phone In Costa Rica
Pre-paid SIM card can be purchased at the San José & Liberia airports and many other locations country-wide. Pre-Paid SIMs can be recharged at the same locations all over the country, so using a pre-paid SIM is a pretty simple deal.
Using a PrePaid SIM in Costa Rica means you must have a quad band unlocked cell phone. The vast majority of US cell phones are NOT unlocked and some (maybe many) are not quad band. They are locked to the company providing the cell service and a pre-paid SIM here will not work.
The airport only sells SIMs from ICE, the old government monopoly phone company. Their SIMs work fine, but a prepaid SIMs from MoviStar provides better coverage, faster Internet, flexible billing ( by the day) and have better customer service. When traveling it’s good to use Viber, WhatsApp, and Line to communicate with no issues. So with a Smart Phone one should have all three of these apps.
Some phones (iPhones and others) may require a half sized SIM (mini-SIM) and as those are not sold here pre-cut in many locations, the vendor must use a die type machine to cut them to size. if he knows what he is doing, no biggie, If not, the cut SIM may not work. Hint: Don't pay until you have installed the cut SIM and prove it is working
When renting a cell phone here, 3G is just fine, but you should insist on 3G phone or rent from a reliable cell phone rental company.