Monthly phone plan or pay-as-you-go: what actually works for English teachers in Korea
Most foreign teachers in Korea end up on a postpaid plan with a two-year lock-in they didn't need. Here's what the carriers don't make obvious: prepaid monthly plans exist, cost less, and you can quit them when your contract ends.
Park English · 2026-08-27 · 3 min read
When you walk into an SK Telecom or KT shop in your first week, the clerk will hand you a postpaid contract. Two years, ₩55,000 a month, unlimited data, a free phone if you stay the distance. You will probably sign it, because everyone else did and you need a working number by Monday.
Then eleven months later your hagwon folds, or you decide Busan isn't for you, and you're on the hook for ₩600,000 in early termination fees because you're eight months short of the contract minimum.
Postpaid vs prepaid, and why it matters
A postpaid plan bills you at the end of the month. You sign for a year or two, they run a credit check, and if you leave early you pay a penalty—usually the subsidy they gave you on the phone, plus a chunk of the remaining term. If you took a "free" Galaxy S23, that penalty is real money.
A prepaid plan charges you up front. You pay ₩20,000 to ₩35,000 around the first of the month, you get your data and your calls, and when the thirty days end you either pay again or you don't. No contract. No exit fee. You can cancel it the week your flight home is booked.
The prepaid option exists at every major carrier—SK Telecom, KT, LG U+—but it is not the plan they lead with, because they make less money from someone who can leave in a month.
What prepaid actually costs
| Carrier | Plan name | Monthly cost | Data | Notes |
|---|---|---|---|---|
| SK Telecom | Prepaid T-Slim | ₩22,000–₩33,000 | 6–12 GB | English support exists but varies by branch |
| KT | Prepaid USIM | ₩20,000–₩28,000 | 5–10 GB | Refill at any GS25 or CU |
| LG U+ | Prepaid Monthly | ₩25,000–₩35,000 | 8–15 GB | Least English, best coverage outside Seoul |
You can top up at any convenience store. The clerk scans your phone number off the Kakao Pay screen or you write it on a slip, you hand over cash or card, it loads in two minutes.
When postpaid makes sense anyway
If your hagwon is stable, you plan to stay two years, and you want a new phone now without paying ₩900,000 up front, a postpaid contract is fine. The subsidy is real. But check the early termination clause before you sign, and make sure you know what "stable hagwon" actually means—ask how long the current foreign teacher has been there, not what the director promises you.
If you brought an unlocked phone from home, or you're fine buying a used one in Yongsan for ₩150,000, prepaid is nearly always cheaper over the length of a typical first contract.
The SIM card
You need a USIM card. It costs ₩5,000 to ₩10,000 depending on the shop. Some prepaid plans include it; some charge it separately. Bring your Alien Registration Card—no ARC, no SIM. Your passport is not enough after the first month.
If you're switching from postpaid to prepaid mid-year, you can port your number. It takes one business day. The new carrier handles it if you ask, but you'll still owe the old carrier any remaining contract penalties.
English support
SK has the most English signage and the most clerks who will try. KT is fine in Seoul, harder in Gyeonggi suburbs. LG U+ is the one where you might need Papago open on your phone the whole time. All three have English websites that are mostly accurate, though the prepaid pages are often two clicks deeper than the postpaid ones.
Some teachers bring a Korean-speaking friend to the shop for the signup. It helps, but it is not required—I have signed two prepaid plans in five years and both times the clerk worked it out with gestures and a calculator.
One thing that varies
Prepaid data does not always roll over. On some plans, unused gigabytes vanish on day thirty-one. Check that when you pick the plan, especially if you spend every weekend on hagwon Wi-Fi and barely use mobile data. A smaller prepaid allotment you actually use beats a larger one you pay for and lose.