Mobile plan · identity verification · banking · everyday apps — these four are all linked together.
"I thought it was because my SIM was prepaid" — it’s actually about a numbering system. Here’s what works before and after you get your ARC.
As of September 2026
Mobile plan · identity verification · banking · everyday apps — these four are all linked together.
If you’re planning to stay in Korea for a few months or more, it’s worth understanding the phone situation ahead of time.
ARC (Alien Registration Card) comes up throughout this article — if you don’t have one yet, read the ARC guide first, since that’s the right order to do this in.
A prepaid SIM bought with just your passport handles calls and data fine, but you won’t be able to open a bank account.
That’s not because it’s prepaid, though — once you understand the real reason, you can plan around exactly what works when.
Korean identity verification (PASS, for instance — an authentication app jointly run by the three major carriers) asks for your name, a 13-digit number, and your carrier. For Korean citizens, that number is the Resident Registration Number; for foreign nationals, it’s the Alien Registration Number assigned when your ARC is issued — the two follow the exact same digit format (Enforcement Decree of the Immigration Act, Article 40-3).
Here’s the full sequence.
Secures your 13-digit Alien Registration Number
Now banking apps, PASS, etc. can verify you
Having an ARC alone doesn’t finish the job — you need to actually activate a line with that number. Prepaid or postpaid doesn’t matter — whether the line carries a 13-digit number is the real variable.
KakaoTalk and Kakao T (taxi-hailing) can both be signed up with a foreign number (confirmed via Kakao’s official customer service) — enter a country code plus a number you actually own in the phone field, and an SMS verification is all it takes.
Since even a foreign number works, a Korean prepaid SIM bought with just your passport works even more smoothly. No ARC or identity verification needed — KakaoTalk and Kakao T are usable from the prepaid-SIM stage.
Messaging and ride-hailing are fine to use while you’re waiting on your ARC. (Payment features like KakaoPay transfers are a separate matter — those need a Korean number plus an ARC.)
These are real cases from a 2025 Newsis news investigation.
The most reliable route is visiting a major carrier’s store (SKT, KT, or LG U+) — bring your ARC and passport and it’s done on the spot.
Budget MVNOs are also a good option — plans often run close to half the price of the big three carriers.
But an MVNO is still leasing network capacity from SKT, KT, or LG U+, so call and data quality are identical to the big three. What matters is that you remember which network your MVNO actually runs on when you sign up — you’ll need that later for identity verification.
Installing the PASS app — PASS is actually a separate app per carrier (PASS by SKT, PASS by KT, PASS by U+). Big-three customers install their own carrier’s app; MVNO customers install the app matching whichever network they’re leasing (e.g., an MVNO on KT’s network uses PASS by KT).
When you go through identity verification — the carrier-selection screen usually shows six options total: SKT, KT, and LG U+ for direct big-three customers, plus three more for MVNO customers leasing each of those same three networks. Pick the one that actually matches your line, out of the six, or the verification code won’t arrive.
The Ministry of Science and ICT announced this on June 30, 2026, and it took effect July 6 — facial recognition is now part of new sign-ups and number transfers across all three major carriers and every MVNO, on every channel, in-store and online alike (device upgrades on the same carrier are excluded).
If facial recognition fails, there’s a fallback — if you have a smartphone, you can verify with a mobile ID (for foreign nationals, the mobile Alien Registration Card). If you don’t have a smartphone, check with your carrier first about what fallback applies to foreign nationals. The resident registration extract is for Korean citizens.
It’s safest to assume ARC holders go through the same process — there’s no indication that having an ARC lets you skip facial recognition. The government itself has said it will "progressively upgrade the system for verifying foreign nationals’ ID authenticity," which suggests the process for foreigners isn’t fully smooth yet.
If you’re hearing that MVNO sign-ups are getting blocked lately, this new rule is likely why — and since there are so many MVNO operators, plenty of them are probably already working fine. There’s no reason to avoid MVNOs altogether; just ask ahead of time whether they support online sign-up and facial recognition before you commit. This should sort itself out operator by operator as the rule beds in.
The "mobile ID" fallback for facial recognition has a foreign-national version called the mobile Alien Registration Card. You can get one if you’re 14 or older with a smartphone in your own name — a chip-embedded ARC (check for the mobile ID logo on the lower left of the card) issues instantly by tapping the card against your phone in the app, while older cards require a visit to an Immigration Office to scan a QR code.
Checklist
KakaoTalk and Kakao T work fine with a foreign number in the meantime
Account opening itself isn’t possible until the ARC arrives
A carrier store visit is most reliable; MVNO sign-ups online may get blocked
Once identity verification clicks into place, everything feels different from there on. Delivery apps, online shopping, secondhand marketplaces, ticket booking, all kinds of reservation services — nearly every Korean app that involves payment requires identity verification. As each of those unlocks one by one, daily life gets noticeably more convenient.
This article is for general information only — requirements for individual services can change over time.