Before you start

An unlocked handset supporting Korean LTE and 5G bands
Passport, for an eSIM or a prepaid SIM
Alien Registration Card, for any line in your own name
A Korean bank account, for auto-debit on most monthly plans

Step-by-step

1
Land connected on a data eSIM
A Korea eSIM bought before flying activates on landing and covers maps, messaging and navigation while everything else is pending. Data-only, so no Korean number and no verification — a bridge rather than a plan.
Mobile appWho: You, before departureActive on landing
2
Add a prepaid SIM on your passport if you need a number
Carrier stores downtown and around Chungjang-ro sell prepaid lines with a real 010 number on a passport alone. Useful immediately for landlords, agents and delivery drivers. It still will not clear real-name verification, because passport-registered prepaid lines have no link to your registration record.
In personWho: You5–10 minutes
3
Once the ARC exists, take a line in your own name
With the ARC and a Korean account you can sign a postpaid contract at a carrier store, or take a much cheaper MVNO plan running on the same networks. Number portability lets you keep the 010 number you have been giving out. Carrier stores complete it in half an hour; MVNO sign-up is usually online and activates in a day or two.
In personWho: YouSame day, or 1–2 days for an MVNO
4
Clear verification with the PASS app
PASS is the smoothest verification route for foreign residents, and it authenticates you into banking, government services and delivery apps. Confirm the carrier holds your name exactly as it appears on the ARC — mismatched spacing, hyphens or middle names are the commonest single cause of failure.
Mobile appWho: YouMinutes once the line is in your name
5
Order home internet, and ask what actually reaches the unit
Fibre is cheap and fast, and the newer estates in Suwan, Cheomdan and Sangmu have it to each unit as standard. The older low-rise and villa stock across Dong-gu, Nam-gu and parts of Seo-gu often runs on a shared building connection where your real speed has nothing to do with the plan you bought. Ask the agent before signing if you work from home.
OnlineWho: YouDays to two weeks
6
Set KakaoTalk up properly
KakaoTalk is how landlords, building managers, colleagues and delivery drivers reach you in Korea. Basic messaging works on a foreign number, but payments, account recovery and identity-linked features expect a Korean 010 line in your own name.
Mobile appWho: YouSame day

Documents you’ll need

Passport, for eSIM and prepaid
Alien Registration Card, for postpaid and MVNO lines
Korean bank account details for auto-debit
An unlocked, band-compatible handset

Things most newcomers don’t know

A number is not an identity — only a line registered to you personally clears verification.

Korean real-name verification checks your line against your registration record, and a passport-registered prepaid line has no such link. So you can call, text and navigate while remaining locked out of banking apps, government portals and most delivery services. Newcomers who think the number was the point spend weeks bewildered about why nothing will accept them.

Source: community-reported

MVNOs resell the same three networks at a fraction of the price with identical coverage.

Korea's budget operators buy wholesale capacity from SKT, KT and LG U+, so you are on exactly the same towers at the same speeds. The trade-offs are Korean-language sign-up flows and a day or two to activate rather than instant in-store setup. Paying a flagship carrier price without needing the bundled services is several times the cost for no measurable difference.

Source: community-reported

Name spelling must be identical across passport, ARC and carrier or verification simply fails.

The check compares strings, not people. A middle name recorded on the ARC but omitted at the phone shop, or a hyphen placed differently, produces a failure with an error message that explains nothing and takes a carrier visit to fix. The phone contract is usually the last of the three to be created, which makes it the one to get right at the counter.

Source: community-reported

In Gwangju the building decides your internet more than the plan does.

The city's housing splits sharply between recent apartment estates wired with fibre to each unit and a large stock of 1980s and 1990s low-rise villas on a shared basement line. The advertised gigabit plan is the same in both; the delivered speed is not. If you work from home, ask what physically terminates in the unit before you sign, not after.

Source: community-reported

Common mistakes to avoid

Assuming a prepaid or eSIM number will pass identity verification for banking and Korean apps.
Registering the line in an employer's or a friend's name and losing control of your own number.
A name mismatch between passport, ARC and carrier record breaking PASS verification.
Letting a prepaid number lapse and losing the line every verification is tied to.
Signing a lease on older villa stock without asking what internet actually reaches the unit.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.