Korean ARN Validator Same checksum as RRN, 7th digit marks foreigners 🔒 Privacy-by-design

Validate any 13-digit Korean ARN (Alien Registration Number, 외국인등록번호) instantly. Identical checksum algorithm to RRN — but the 7th digit (5/6/7/8) marks foreign residents. Auto-extracts birthday, gender, and birth century. Runs entirely in your browser — your number never leaves the page.

This tool runs 100% client-side in your browser. Your ARN is never transmitted to any server, stored in localStorage/cookies, or cached. Refreshing the page wipes the input instantly. Share-URL, copy, and save buttons are intentionally omitted to prevent accidental disclosure of personal data. You can verify this in DevTools (F12 → Network tab).

ARN vs RRN — same algorithm, different 7th digit

ARN — Alien Registration Number

YYMMDD-Xnnnnnn (13 digits)

Issued by Korea Immigration Service. For foreigners staying 90+ days (F-2/F-4/F-5/F-6/E-7 etc.). 7th digit: 5/6/7/8. Validated by this tool.

RRN — Resident Registration Number

YYMMDD-Xnnnnnn (13 digits)

Issued by local 동사무소 to Korean nationals at age 17. Same length and checksum. 7th digit: 1/2/3/4. Same length, but this tool flags it as not-an-ARN.

Alien Registration Number (13 digits)

0 / 13 digits Enter your Alien Registration Number

※ Your input is never stored or transmitted. Validated entirely inside your browser.

Awaiting input

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🔒 Sharing disabled (personal data)

※ Copy/share/save buttons are intentionally omitted. Your ARN is government-issued personal information.

7th-digit reference

First 6 digits = birthday (YYMMDD). The 7th digit alone distinguishes ARN from RRN.

Code	Class	Birth century
1	Korean male (RRN)	1900–1999
2	Korean female (RRN)	1900–1999
3	Korean male (RRN)	2000–2099
4	Korean female (RRN)	2000–2099
5	Foreigner male (ARN)	1900–1999
6	Foreigner female (ARN)	1900–1999
7	Foreigner male (ARN)	2000–2099
8	Foreigner female (ARN)	2000–2099
9	Korean male (RRN, 1800s)	1800–1899
0	Korean female (RRN, 1800s)	1800–1899

※ Defined by Article 40, Enforcement Decree of the Immigration Act (출입국관리법 시행령 제40조). 2026-05.

Visa types and ARN issuance

All long-term residents (90+ days) receive an ARN regardless of visa class. The ARN stays the same across visa changes, extensions, and reissues.

F-2 Residence — long-term residents (Korean spouse before marriage etc.)
F-4 Overseas Korean — Korean diaspora returning
F-5 Permanent Resident — indefinite stay, ARN permanent (card renews every 10 years)
F-6 Korean Spouse — marriage migrant
E-7 Skilled Worker — designated activities (engineer, IT, R&D, etc.)
D-2 / D-10 Student / Job Seeker — academic and post-grad
H-2 / H-1 Working Visit — Korean diaspora workers, working holiday

Short-term visas (C-3 tourism, B-1, B-2, etc., under 90 days) do not receive an ARN — your passport substitutes.

How the checksum works

Strip non-digits to get d[0..12].
With weights W = [2, 3, 4, 5, 6, 7, 8, 9, 2, 3, 4, 5], compute S = Σ d[i] × W[i] for i=0..11.
Expected check digit check = (11 − S mod 11) mod 10.
If check === d[12], the format is valid for ARN/RRN.
If the 7th digit (d[6]) is 5/6/7/8, it's an ARN. Otherwise, it's an RRN (or undefined code).

Same algorithm as RRN — Korean standard since 1968, unchanged for 50+ years.

FAQ

What is a Korean ARN?

ARN (Alien Registration Number, 외국인등록번호) is a 13-digit identifier issued by the Korea Immigration Service to all foreigners staying in South Korea for 90+ days. It functions like a Korean Resident Registration Number (RRN) for residents and is required for banking, mobile contracts, health insurance, taxes, real estate, and most legal documents. Format: YYMMDD-Xnnnnnn where the 7th digit indicates birth century plus foreigner status.

How do I find my ARN?

Your ARN is printed on the front of your 외국인등록증 (Alien Registration Card / Residence Card). If you've lost the card or forgotten the number: check HiKorea (www.hikorea.go.kr) and log in with your card credentials, call 1345 (Korea Immigration Hotline) which supports 19 languages including English, Chinese, Vietnamese, and Japanese, or visit your nearest Korea Immigration Office in person with your passport.

Does my ARN change when I renew my visa?

Generally, no. Your ARN is issued upon first registration in Korea and stays the same through visa changes (e.g., D-2 → E-7), extensions, card reissues (lost or damaged), and status changes. F-2 (residence), F-4 (overseas Korean), F-5 (permanent resident), F-6 (Korean spouse), and E-7 (skilled professional) all preserve the original ARN. The only common exception is when you leave Korea for several years and your immigration record is fully closed; on a new entry, Immigration may assign a new ARN. Confirm with HiKorea or 1345 before assuming.

Can I use my ARN as a Korean ID?

Yes, in nearly all cases. ARN is treated identically to RRN for banking, mobile phones, real estate contracts, the four social insurances (national health, pension, employment, industrial accident), tax invoices, credit cards, and property registration. A small number of legacy identity-verification systems (mobile carrier PASS, some certificate-based services) still don't fully support ARN, so you may occasionally need to visit a foreigner-friendly bank branch (KB Kookmin, Shinhan, Woori) in person with your registration card.

What's the difference between ARN and RRN?

Both are 13 digits with identical format and checksum algorithm. The only structural difference is the 7th digit: 1/2 = Korean national born in 1900s (M/F), 3/4 = Korean national born in 2000s (M/F), 5/6 = Foreigner born in 1900s (M/F), 7/8 = Foreigner born in 2000s (M/F). Functionally, both grant equivalent rights for daily life in Korea. RRN is for citizens (issued by your local 동사무소 at age 17), while ARN is for residents on long-term visas (F-2, F-4, F-5, F-6, E-7, D-2, D-10, etc.) issued by Korea Immigration Service.