For a trip under a month, a data-only eSIM (roughly ₩25,000–₩35,000 for a week) is the easiest option if your phone supports it. Want a Korean number for calls and texts? Get a prepaid tourist USIM on your passport at the airport. For longer stays you can't jump straight to a cheap monthly contract — Korean postpaid plans (about ₩39,000+ per month) require an ARC and usually a Korean bank account. Until your ARC arrives, bridge the gap with a prepaid MVNO (알뜰폰), around ₩20,000 per month on a passport. The real decision is whether you need a Korean number for identity verification, not just the lowest data price. Check your phone is unlocked before you buy anything.
Getting online in Korea is easy. Getting a proper Korean number — one that passes identity verification for banking and delivery apps — is the part that trips foreigners up. They are not the same thing, and the difference decides which plan you actually need.
Which one are you?
Pick your situation first, then read the section that matches:
Short trip (a few days to a few weeks): an eSIM or a prepaid tourist SIM. You mostly need data, maybe a local number.
Long stay, no ARC yet (students, working-holiday, new arrivals): a prepaid MVNO on your passport.
Settled, ARC in hand: a postpaid contract, or a cheaper MVNO monthly plan tied to your bank account.
Every option below assumes your phone is carrier-unlocked. A locked phone from home won't accept a Korean SIM or eSIM, and that's the single most common mistake.
Under 1 month: a data eSIM
If your phone supports eSIM — iPhone XS or newer, Galaxy S20 or newer, Pixel 3 or newer — buy one online before you fly and you're connected the moment you land at Incheon. No counter, no queue, no physical SIM to swap.
Unlimited-data tourist eSIMs run roughly ₩25,000–₩35,000 for a week, more for longer or truly unlimited plans. Global providers (Airalo, Saily, Holafly) are the easy default; local Korean eSIMs are often a little cheaper for the same data but take more setup. The catch: most travel eSIMs are data-only, so you won't get a Korean 010 number. For tourists that rarely matters — maps, translation, and KakaoTalk all run on data.
Good for: travelers who mainly need data and want zero hassle on arrival.
A few weeks to 6 months: a prepaid USIM
If you want a real Korean number for incoming calls and texts, a prepaid USIM is the classic move. All three big carriers — SK Telecom, KT, and LG U+ — sell them, and you can buy at arrival-gate counters at Incheon, Gimpo, Busan, and Jeju, at convenience stores, or reserve online and collect on arrival to skip the wait.
You only need your passport, and again, an unlocked phone. A Korean number unlocks the apps that actually run daily life here: banking, Coupang, Baemin delivery, and restaurant waitlists all require SMS verification. Students on short programs, working-holiday arrivals waiting for their ARC, and long tourists are the natural fit.
Good for: anyone who wants a local number without committing to a contract.
The postpaid trap: why you can't just sign up
Here's where foreigners get stuck. A Korean postpaid contract (후불요금제) — the normal monthly plan locals use — gives you a permanent number with full data, calls, and texts for about ₩39,000–₩80,000 per month on the big three, with good English support. But you can't get one on day one.
Postpaid contracts require an ARC (Alien Registration Card, 외국인등록증) — your Korean residency ID — and usually a Korean bank account for automatic monthly withdrawal. The ARC itself takes several weeks to be issued after you arrive and register. So no matter how long you're staying, your first month or two in Korea cannot be postpaid. Plan around that gap instead of being surprised by it.
Long stay but no ARC yet? Use a prepaid MVNO
The bridge for that gap is a prepaid MVNO (알뜰폰) — a budget carrier that leases the big three's network and resells it on your passport only, no ARC required. Foreigner-friendly operators with English support, like Chingu Mobile and Woori Mobile, run around ₩20,000 per month for a solid data allowance. Same coverage as the big three, roughly half the price, less English hand-holding.
This is the cheapest sensible way to have a working Korean number during your first months. When your ARC arrives, you can either keep the same number or switch to a full postpaid or cheaper MVNO monthly plan.
One thing to check: to later link your number to your ARC for online identity verification, some MVNOs require a 3-month-or-longer plan. If verification matters to you, don't buy the shortest option.
The identity-verification catch (본인인증)
This is the part travel blogs skip, and it's the real reason your choice of number matters. Many Korean services — banking apps, Toss, delivery apps like Baemin and Coupang Eats, ticketing sites, even some Wi-Fi signups — require 본인인증 (identity verification) through a Korean mobile number registered to your name and, for foreigners, tied to your ARC.
A data-only eSIM or a short tourist SIM won't pass this check. If your plan for Korea includes ordering delivery, using local banking, or booking through Korean apps, you need a real Korean number registered to you — a prepaid MVNO before your ARC, or a postpaid/MVNO monthly plan after it, not a tourist data SIM.
Before you leave Korea: cancel your postpaid plan
Postpaid contracts in Korea are tied to your identity, not just your number. If you leave the country without formally cancelling, the unpaid balance follows your ARC and can surface the next time you return or re-register. Cancel in person or through your carrier before departure, and keep the confirmation. Prepaid SIMs and eSIMs simply expire, so there's nothing to cancel.
How to choose, and where to buy
Just visiting, need data: eSIM before you fly.
Visiting, want a Korean number: prepaid tourist USIM at the airport, passport in hand.
Staying months, ARC not yet issued: prepaid MVNO on your passport (~₩20,000/month).
Settled with ARC + bank account: postpaid contract, or a cheaper MVNO monthly plan.
Buy tourist SIMs and eSIMs online in advance or at airport counters; buy MVNO and postpaid plans through the carrier's app or a foreigner-focused reseller once you're set up. Whatever you choose, confirm your phone is unlocked and bring your passport (and ARC, once you have it).
Phone Plan Finder — not sure which SIM fits your trip? Answer a few questions about your stay length, whether you need a Korean number, and your ARC status, and see the option that fits with where to buy it.
Frequently asked questions
Can I get a Korean phone plan without an ARC? Yes, but only prepaid. Tourist eSIMs and prepaid USIMs need just a passport, and so do prepaid MVNO plans. Standard postpaid monthly contracts require an Alien Registration Card and usually a Korean bank account.
Will a tourist eSIM let me use Korean banking and delivery apps? Usually no. Those apps require identity verification through a Korean number registered to you and your ARC. Data-only eSIMs and short tourist SIMs don't meet that requirement.
How much should I budget per month for a phone in Korea? Before your ARC, around ₩20,000/month on a prepaid MVNO. After your ARC, roughly ₩39,000–₩80,000/month for big-carrier postpaid, or less on an MVNO monthly plan.
Does my phone need to be unlocked? Yes. A carrier-locked phone from home won't accept a Korean SIM or eSIM. Unlock it with your home carrier before you travel.
Where do I buy a SIM at the airport? SK Telecom, KT, and LG U+ all run counters near the arrival gates at Incheon and other international airports. You can also reserve online and pick up on arrival to avoid the queue.