The Alien Registration Number in Korea: What It Is and Where It Appears

What the number is

The alien registration number (oegugin deungnok beonho) is the 13-digit identifier printed on your Alien Registration Card (ARC). It is the foreign resident’s equivalent of the Korean citizen’s resident registration number (jumin deungnok beonho), and in Korea it functions as your identity number across banking, telecoms, health insurance, tax and most online services.

Format

YYMMDD-XXXXXXX

• First six digits — your date of birth in YYMMDD form
• Hyphen — the visual separator (not part of the value)
• Last seven digits — a sequence assigned when your registration is issued

The first six digits being your birth date is why the number ‘looks familiar’ to the person whose card it is — but the number is issued only when you register, so it is not something you can predict before your ARC is processed.

Where you find it

The number appears in two places you will use routinely:

• On the Alien Registration Card itself — printed on the front, usually below your name and nationality
• On documents issued against your registration — your certificate of alien registration, and on paperwork from banks, the tax office, and immigration that references your record

If you lose the card, the number itself is on your registration record, and a reissue application replaces the physical card. Report a lost card promptly — the card is the proof of your lawful stay, and the number is tied to services that assume you can present it.

If you have a Residence Card rather than the older card format, the same number appears on it; the term ‘alien registration number’ is still used for the identifier itself.

What opens only once you have it

Until your alien registration number exists, a surprising amount of Korean life stays closed. The number is what most systems key on:

• Bank accounts — most banks require the ARC and its number for a full account. Some offer restricted passport-based accounts to new arrivals, usually with transfer limits.
• Postpaid phone contracts — telecoms verify against the number. Prepaid SIMs are the interim option before registration.
• National health insurance — enrolment is tied to your registration record.
• Online identity verification — the verification layer used across Korean websites (ticketing, delivery apps, government portals) is built on resident and registration numbers.
• Tax — the alien registration number is what the tax authorities use to identify you as a taxpayer.

This produces a familiar deadlock for new arrivals: you need a phone for the bank, an account for the phone, and the number for both. The usual route out is a prepaid SIM first, then registration, then the full account. For the application process and the 90-day deadline, see our alien registration guide.

How it differs from the Korean resident registration number

Both numbers are 13 digits and both use your birth date in the first six positions, so they look the same shape. The differences matter:

	Resident registration number	Alien registration number
Holder	Korean citizens	Foreign residents
Issued at	Birth	Alien registration (stays over 90 days)
First six digits	Date of birth	Date of birth
Role	Citizen identity number	Foreign resident identity number

Because the two systems share a format, systems that accept one will accept the other’s shape — which is exactly why your number works for identity verification and banking. The seventh digit encodes gender and birth century, and the final digit is a check digit, as it is for the citizen number. Treat the number as sensitive personal data: in Korea, collecting, using or circulating another person’s registration number without a legal basis is restricted.

Practical points

A few things worth knowing before and after registration:

• Register early. The number exists only after you apply for alien registration, and stays over 90 days require it. Apply within 90 days of entry — see the alien registration guide for timing and documents.
• Keep the card accessible. Many transactions expect you to produce the card or quote the number, so keep a copy separate from the card itself.
• The number stays with you. It does not change when you renew your ARC or change your address; it is tied to your foreign resident record.
• Report changes. Address changes must be reported within 14 days; employer, school or status changes too. A lapsed report shows up as a compliance item at your next extension.

The number is not a visa and says nothing about permission to work or stay — it is the identifier attached to your lawful registration. Those questions are decided by your status, not the number.