Still on a prepaid plan in Korea? Here's when — and how — to switch

Prepaid vs Postpaid in Korea — The Complete Guide for Expats. Not sure whether to stick with prepaid or switch to a postpaid or MVNO plan in Korea? Mangrove breaks down everything you need to know, including how to transfer your number.
Still on a prepaid plan in Korea? Here's when — and how — to switch

Prepaid made sense at first — but things change

When you first arrived in Korea, a prepaid SIM was probably the easiest choice. Pick one up at the airport or a convenience store, activate it with your passport, top up when needed — no paperwork, no commitments. Simple. But the longer you stay, the more the cracks start to show.

Data costs more per gigabyte, top-up deadlines can catch you off guard, and if your balance expires at the wrong moment, you might lose your number entirely. Worse, Korean banking apps, delivery platforms, and financial services sometimes reject prepaid numbers for verification — which is a real problem when you're trying to settle in properly.

Prepaid, postpaid, or MVNO — what's the difference?

type

Prepaid

Postpaid

MVNO (budget carrier)

Sign-up requirements

Passport only

ARC + credit history

ARC required, lighter screening

Monthly cost

Higher per use

Flat rate, cost-effective

20–40% cheaper than big 3

Data

Top up when depleted

Unlimited or large bundles

Wide range of plans

Number stability

Risk of expiry

Stable

Stable

Financial app compatibility

Sometimes blocked

Works in most cases

Works in most cases

For expats on work visas or long-term stays, an MVNO (알뜰폰) is often the sweet spot. You get the same KT, SKT, or LG U+ network coverage at a significantly lower monthly rate.

How to cancel your prepaid plan and transfer your number

Step 1 — Cancel your prepaid plan. Contact your current carrier's customer service line — KT has English support at 1588-0010, SKT at 1599-0011 — or use the official app to request cancellation. Before you do, check whether any remaining balance is refundable. Some prepaid products don't return unused credit.

Step 2 — Transfer your number (MNP) Korea has a well-established Mobile Number Portability (MNP) system, which means you can keep your existing number when switching carriers or plan types. Visit a store or use the official app of your new carrier and select "number transfer" (번호 이동) when signing up. You'll need your ID (passport or ARC) and your current carrier's account details.

Step 3 — Choose your new plan

The big three carriers — KT, SKT, and LG U+ — offer postpaid plans ranging from around ₩30,000/month for limited data up to unlimited options. If you'd prefer an MVNO, providers like HelloMobile, KT M Mobile, and others can be compared side by side on the government-run portal at 알뜰폰허브.kr.

When admin in Korea feels like too much

Phone contracts are just one piece of a larger puzzle. For many expats — especially those on corporate transfers or new work visas — the administrative load of settling into Korea can feel overwhelming: housing deposits, contract terms in Korean, bank account requirements, and more.

Mangrove exists to take that friction away. Our co-living spaces require no deposit, offer flexible lease terms from one to four months, and come fully furnished — so you can focus on getting settled rather than buried in paperwork.

We also help residents navigate the everyday logistics of living in Korea, from telecom to residency admin.

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