For those of you with Verizon phones, you are in luck as South Korea is pretty much 100% CDMA-based. GSM phones like anything from AT&T and T-Mobile won’t work in South Korea no matter what they say unless you have a “world” phone that supports CDMA along with GSM.
To use your Verizon phone in South Korea, you will want to make sure you have the “International Dialing” feature in your plan, make sure you have it.
Second, you need to dial *228 on your Verizon phone and press 2 to obtain updated PRL prior to traveling to Korea! !MOST IMPORTAN