Using an iPhone 4S in South Korea

Question

My brother will soon be going to South Korea to teach English and he is wanting to make sure that his phone will work properly with a local carrier. The phone is SIM unlocked (we verified it with an Orange UK SIM card that I picked up last summer in England). So, does anyone know of a South Korean carrier that supports iPhones?

The iPhone 4S is from Sprint in the USA originally and they unlocked the GSM SIM slot for me because I was going to spend some time in the UK.

Will this GSM-unlocked CDMA phone work with any South Korean carriers?

Answer 1

It will work on KT (they even sold the 3GS which wasn't CDMA), and possibly others.

He may need to get the IMEI registered with the network before the SIM will work in it though as they are very protective over their networks (this was true up until 2010 at least, although they may have become more relaxed on this since then).

Answer 2

SK Telecom and KT (Korea Telecom) are both vendors of the iPhone, but they are CDMA providers I believe. I'm not sure

Answer 3

Apple maintains a list of all carriers that work with iPhone, so if no one here has first-hand experience of using an authorized unlock Sprint phone with one of the Korean carriers, you can always use the contact information for both carriers to ask how you might spend some money with them while in country.

• http://support.apple.com/kb/HT1937
• http://support.apple.com/kb/HT3939

The second link shows that the Sprint 4s is A1387: iPhone 4s (CDMA model), so that means it is capable of working with both CDMA voice networks and GSM voice networks. Since you've already unlocked for GSM, that might be your easiest bet since most carriers offer prepaid SIM that just works. It's really up to the carriers in Korea, however since they could not service a phone that's not enrolled and you will need their help to get the CDMA MEID registered before it would work on a CDMA network. You might need their help registering your IMEI or they might be open to most devices.