The Complete Guide to Korean SIM Cards & Mobile Plans for Foreigners (2025 Update)

The No-Stress Playbook to Korean SIM Cards & Phone Plans (2025)

Get a local number first. Almost everything here — deliveries, banking OTPs, taxi apps — assumes you have a Korean phone number. (In My Korea)

TL;DR (Quick Picks)

• Here ≤90 days? Get a prepaid (or eSIM) data plan you can pick up at Incheon Airport. It’s fast, English-friendly, and activation is minutes. (roaming.kt.com)

• Here long-term? Start with prepaid. After you receive your ARC (foreigner ID) + local bank card, switch to postpaid or an MVNO (알뜰폰) for better monthly value. Keep your number via number portability (번호이동). (Sim card Korea – CHINGUMOBILE)

1) Decide: Prepaid, Postpaid, or eSIM?

Many airport counters and official carrier desks support tourists in English and stock physical SIMs; eSIMs and pick-ups can be ordered online in advance. (roaming.kt.com)

2) Documents & Timing — What to prepare

Prepaid: Passport is enough.

Postpaid: Passport + ARC + bank card + local address (common requirements). (Fragment Seoul)

“ARC (외국인등록증) is the de-facto ID for foreigners staying over 90 days.” (Sim card Korea – CHINGUMOBILE)

3) Where to buy — Airport, City, or Online?

4) The Big Three vs MVNO (알뜰폰)

• Broad 4G/5G coverage nationwide; SKT/KT slightly wider outside metros; LG U+ often sharp on price in cities. (In My Korea)

• Uses big-three networks at lower monthly prices; ideal after you have ARC + bank card; sign-up often online. (Lingua Asia)

“Students and budget users often save the most with MVNO plans while keeping the same network quality.” (Sim card Korea – CHINGUMOBILE)

5) Coverage, Speed & “Unlimited” Reality

• Korea’s mobile internet is fast and dense in cities; 5G is standard in metro areas.

• Unlimited data typically includes a high-speed allowance; speeds then throttle (acceptable for maps/messaging, slower for HD video). Always check the plan’s fair-usage policy. (skroaming.com)

6) Keep your number when you switch (번호이동)

“Mobile number portability lets you keep your number when changing providers.” (home.mobilenumberportability.com)

7) Step-by-step: the smoothest setup

1. At airport arrivals, buy a prepaid SIM/eSIM. Insert/scan on the spot. (roaming.kt.com)

2. Confirm data works; place one local test call if your plan includes voice.

8) Common traps & how to dodge them

“Ask about activation fees, SIM issuance fees, and early-termination penalties before you sign.” (Fragment Seoul)

• Roaming leftovers: Turn off your home-SIM data to avoid surprise roaming.

• eSIM expectations: Some “tourist eSIMs” are data-only; you won’t get a local number for SMS verifications. (skroaming.com)

• Autopay mismatch: Postpaid usually needs a Korean card; if you only have a foreign card, stay on prepaid. (Fragment Seoul)

9) Quick compatibility checklist

• Unlocked phone (test with any other SIM or confirm with your home carrier). (우리통신(영어))

• eSIM-capable device if you prefer QR activation (iPhone 13+/many recent Androids supported). (skroaming.com)

• For postpaid: ARC + address + Korean payment method ready. (Fragment Seoul)

10) Real-world scenarios (pick yours)

• Pre-order a data-only eSIM; add a cheap local voice add-on if needed for calls. Airport pick-up is your backup plan. (krsim.net)

• Start prepaid for the first month. After ARC, move to an MVNO unlimited plan to cut costs; keep your number via portability. (Lingua Asia)

• Go postpaid with your ARC + payroll card once housing is set. If you need a device, compare total cost over 24 months including any early-exit fee exposure. (Fragment Seoul)

11) Handy places & helplines

• Airport desks (Incheon T1/T2): KT/SKT/LG U+ counters; T1 has counters with extended or 24-hour hours. (roaming.kt.com)

• Lost SIM/phone: Visit any carrier branch with passport/ARC for a replacement SIM and line reissue. (Policy varies; ask your provider.) (Fragment Seoul)

12) Copy-paste mini-scripts (for the counter)

“I need a prepaid SIM with data + local number for 30 days. Can I extend online?”

“I have my ARC and Korean card. Which postpaid or MVNO plan is best for 20–30 GB and hotspot?”

“I want to port my current number (번호이동). What do you need from me?”

13) One-page summary (save this)

• Start prepaid/eSIM → get ARC/bank card → switch to postpaid or MVNO → keep your number. (home.mobilenumberportability.com)

• Buy at airport for speed; online for savings; city stores for contracts. (roaming.kt.com)

• Read the FUP and fees. If unsure, choose flexibility first. (skroaming.com)

Final word

Find Your Home. The Rest Gets Easy.

“Secure the right place first — phone plans, banking, and daily life click into place after that.”

• Responsive support from day one: We handle the back-and-forth with landlords before move-in and long after.

• Fast, secure payments: Simple checkout with clear status every step of the way.

• Broad inventory, zero guesswork: From compact studios to coliving — filtered for foreigner-friendly terms.