Ana signed a two-year contract with a big carrier on her first day in Seoul, at the airport, with a new phone included. ₩89,000 a month.
Six months later her Korean colleague showed her his plan: unlimited data on a budget carrier for about a third of the price, using his old phone.
In Korea your phone number is also your digital ID: banks, delivery apps and government sites verify you through it. So it’s worth getting a number in your own name early, but you rarely need an expensive contract to do it.
Your options
| Option | What you need | Good for |
|---|---|---|
| Prepaid SIM or eSIM | Passport | First weeks, before your ARC |
| Budget carrier (알뜰폰, MVNO) | ARC, often a Korean bank account | Most long-term residents |
| Big three contract (SKT, KT, LG U+) | ARC, Korean bank account or card | Buying a new phone on installments |
Budget carriers run on the big three networks, so coverage is the same. You give up flagship store service and phone subsidies.
Step by step
Week 1: prepaid eSIM with your passport, so you can use maps and KakaoTalk.
Weeks 3–6: your ARC arrives. Sign up for a budget plan online or at a store, keeping your number if the carrier allows it.
Then: use the number to verify your bank account and delivery apps.
A plan registered in an employer's or friend's name, which breaks every identity check. A long contract signed on day one with a pricey new phone.
A number in your own name, spelled exactly as on your ARC. Bring an unlocked phone from home if it supports Korean bands.
Leaving Korea? Cancel your plan before you fly. Unpaid phone bills can follow you, and some carriers report them, which can cause trouble if you ever come back on a new visa.
Identity checks (본인인증)
Korean sites ask you to verify with “휴대폰 본인인증.” You choose your carrier, enter your name, date of birth and ARC details, and type in a code sent by text. It only works if the carrier’s records match your ARC exactly, so check the spelling when you sign up.
Next: your ARC, if you haven’t registered yet, and health insurance.
Sources: Ministry of Science and ICT (MVNO guidance); carrier sign-up requirements for foreign residents.
Written from the laws and official notices in force on the date above. Rules change and every case is different, so check with the office named in the article before an important decision. Spotted something out of date? Tell us.