Picture this: you've just landed at Incheon, it's 11pm, your Korean is nonexistent, and your phone battery is at four percent. The immigration line took ninety minutes. You've got a suitcase, a carry-on, and absolutely no data. The KakaoMap link your new employer sent you is saved as a screenshot — thankfully — but your guesthouse host has been trying to reach you for the last hour and has no idea where you are. You find a bench, plug in, and stare at the row of brightly lit carrier booths just beyond the baggage carousel, wondering which one to walk into.

I've been in Korea for three years now, and I remember that exact moment. Let me save you the confusion.

Your First Move: The Airport Booths

As soon as you clear customs and step into the arrivals hall at Incheon Airport Terminal 1 or Terminal 2, you'll see dedicated booths from KT, SK Telecom, and LG U+ — Korea's three major carriers. They all sell tourist prepaid SIMs that require only your passport, no Alien Registration Card (ARC) needed. These SIMs come with a Korean "010" phone number and LTE data, and they're genuinely fast. The staff usually speak enough English to get you set up in five to ten minutes.

Prices vary depending on how many days and how much data you want, but as of recent reports, tourist-oriented data SIMs start somewhere around ₩25,000 to ₩55,000 for 30 days of data (verify current pricing at the booth, as these change). Some packages include unlimited calls within Korea; others are data-only. If you're only here for a short trip, these are fine. If you're moving to Korea, they're a stopgap — an important one, but a stopgap.

You can also pick up prepaid SIMs at convenience stores like CU, GS25, or 7-Eleven once you're in the city. The selection is similar, though the airport is genuinely the most convenient option if you need to be connected right away. Services like Trazy, Klook, and Chingu Mobile also let you pre-order a SIM or eSIM online before you leave home, with pickup available at the airport. If you're the type who likes to have things sorted before the flight, that's a solid option.

The eSIM Shortcut — And Its Traps

International travel eSIMs from providers like Airalo are a popular choice, and they work well for Korea. Airalo offers Korea eSIMs running on the KT and LG U+ networks, activated when you first connect, starting from a few euros for short-duration data packages. You install it before you leave, you land, you have data. Simple.

But there are two things you need to know. First, most international eSIMs are data-only — they give you internet access but not a Korean phone number and not the ability to receive local SMS messages. For tourists, that's usually fine. For someone setting up life in Korea, you'll eventually need a real number for OTP verification on Korean apps and services.

Second, and this catches people off guard: not every phone handles Korean eSIM activation equally. US-carrier-locked iPhones frequently can't activate Korean SIMs or eSIMs properly. Unlocked international iPhones are generally fine. US versions of the Google Pixel have been reported to have difficulties activating eSIMs on Korean carrier networks — this is still a live issue as of early 2026, so if you're bringing a US-market Pixel, check the current situation on r/Living_in_Korea before you rely on it. The safest approach is to activate a travel eSIM before you board the flight so you're not troubleshooting in the airport.

The Pre-ARC Limbo (And Why It's Annoying)

If you're staying in Korea for more than 90 days on a long-term visa, you'll need to apply for your Alien Registration Card (ARC) at the local immigration office. The ARC is basically your official ID as a foreign resident, and it's the key that unlocks most of Korean digital life. The problem is that it takes anywhere from two to six weeks after you apply to actually arrive — and you have to live in Korea during that gap.

The three major carriers — KT, SK Telecom (SKT), and LG U+ — require your ARC before they'll set you up with a standard postpaid plan. That means during your first few weeks, you're limited to tourist prepaid SIMs. These will keep you connected, and they do give you a Korean phone number. But that number is technically a "prepaid foreign tourist" number, and some Korean services treat it differently. Signing up for banking apps like KakaoBank or Toss requires ARC as well as a Korean phone number. The situation with delivery apps like Coupang Eats and Baemin varies — sometimes a prepaid number works for SMS OTP verification, sometimes it doesn't, often depending on the app version and your specific circumstances. Expect friction, not impossibility.

The honest summary of pre-ARC life: you'll have data and calls, but Korean digital services — especially anything involving financial verification or identity — will be frustrating or inaccessible. Plan accordingly. Make note of what you absolutely need (Kakao for chatting with colleagues and landlords is usually fine, for example) versus what can wait until the ARC arrives.

What You Can Actually Do Without ARC: A Realistic Picture

Kakao Messenger generally works with a prepaid SIM number, which means you can communicate with Korean colleagues and coordinate with your landlord from day one. Naver Maps and KakaoMap work without any phone account at all — just WiFi. Public transit apps are similarly accessible. Coupang's shopping platform sometimes works, sometimes doesn't, for new foreign accounts without a resident-linked number — some expats report success, others hit walls; it's not consistent.

Korean banking is essentially unavailable without ARC. Even the banks that are more foreigner-friendly in terms of opening accounts (Shinhan, Woori, and sometimes IBK have been cited) still need to verify you through a Korean phone number and usually the ARC itself. Wise and other international money transfer apps can fill the gap for sending or receiving money internationally during this period.

Getting a Real Plan: After the ARC Arrives

Once you have your ARC in hand, the options open up significantly. You can walk into a KT, SKT, or LG U+ store with your ARC and passport, and get set up with a proper postpaid monthly plan. Standard plans from the big three start around ₩35,000-₩50,000 per month for moderate data and go up to ₩80,000-₩100,000+ for unlimited data tiers — check current pricing at each carrier's website or store, as plans change frequently.

But here's what many foreigners miss: MVNOs. These are mobile virtual network operators — companies that rent network access from the big three and resell it at lower prices under their own brand. In Korean they're called 알뜰폰 (literally "smart phone" or "thrifty phone"). The signal quality is identical to the parent carrier's because it literally is the same towers. KT M Mobile (KT 엠모바일) has an English-language website and runs on KT's network, making it one of the more foreigner-accessible options. Other MVNOs include Hello Mobile and various LG U+ 알뜰폰 brands.

MVNO plans can come in significantly cheaper than the big three — monthly plans with reasonable data allocations (5-20GB) often run ₩15,000-₩30,000 per month. If you don't need unlimited data and you're comfortable navigating a Korean-language website (or bringing a Korean-speaking friend to the store), MVNOs are worth considering. The trade-off is that English customer service is hit-or-miss, and dealing with any issues that require human support can require some Korean or patience.

The most foreigner-friendly approach — especially if you're in Seoul — is to head to a telecom shop in Itaewon or another expat-heavy neighborhood where the staff are used to helping foreign residents. These shops can often help you compare plans across carriers and handle the paperwork. Bring your ARC, your passport, and a credit or debit card for the monthly payments.

The Long Game

The moment your ARC arrives and you get your proper postpaid Korean number, things click into place. Coupang starts working. Banking apps can be set up. Delivery apps cooperate. Kakao Pay links to your bank. It's almost comically smooth after the pre-ARC frustration — like the city just decided to let you in.

The airport SIM gets you through the first few weeks. The ARC gets you into the system. Between those two milestones, lower your expectations for Korean digital services and lean on what does work: international eSIMs for data, Kakao for chat, and the knowledge that the annoying part is temporary. Korea's mobile infrastructure is genuinely excellent — once you're past the ID verification hurdles, it's one of the best-connected countries you'll live in.

One last practical note: when you switch from your prepaid tourist SIM to your ARC-linked postpaid plan, you can usually keep your 010 number through a number transfer process (번호 이동). Ask about this at the carrier store — it's worth keeping the same number rather than having to update contacts again.