Hi! This is Koreabylocal. 

If you want to get a SIM CARD, consider travel period first and check the card plan. 

Here is travel tips! 

1. Online 

Buy online before arrival and take a sim card at the airport! It is the easiest and cheapest way to purchase the card. 

1)  https://roaming.kt.com  (roaming KT) 

2)  https://krsim.net  (Korea Sim card) 

Make reservation first and pick up the card at the airport. 

Location : https://www.airport.kr/ap/en/svc/getFacilityMain.do# 

2. Airport Desk 

If you arrive at the Incheon, not buying Sim card then visit Airport roaming Desk. It is a little bit more expensive then Way 1(online) but this is also highly recommended. 

We have SKT, LG U+,KT , 3 telecom service providers 

3. Offline

Visit major convenience stores. 7 eleven, GS25, CU provide SIM card! 

*Sim card user guideline 

https://roaming.kt.com/ib/eng/cts/sim_guide.asp 

Stay connected in KOREA!