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Korea RRN Check

Local processing · not uploaded

Validate Korean Resident Registration Numbers (RRN) online: 13 digits — first 6 are the birth date, the 7th marks century/gender, and the last is a check digit verified by the pre-2020 weighted mod-11 algorithm.

Sample (click to fill): 800101-1234560

Number—
Date of birth—
Gender—
Validation—

How the Korean RRN is structured

A Korean RRN has 13 digits in the form YYMMDD-SXXXXXC:

Algorithm: multiply the first 12 digits by weights 2 3 4 5 6 7 8 9 2 3 4 5, sum, take modulo 11, then the check digit is (11 − remainder) mod 10. Note: since Oct 2020 digits after the 7th are randomized, so newer numbers may no longer satisfy this checksum.

How to use

1

Paste or type the ID number above (use the sample to try it out)

2

Click “Check”, and the tool verifies structure and check digit locally in your browser

3

See instantly whether it is valid — nothing is uploaded, no real identity is looked up

✅What this tool does

  • Parse date of birth from the first 6 digits; century from the 7th
  • Determine gender from the 7th digit (odd male / even female)
  • Verify the last check digit by the pre-2020 weighted mod-11

💡Tips

  • Valid does not mean it exists: only encoding rules and checksum are verified, no personal data is looked up
  • Do not enter other people’s real ID numbers — protect personal privacy
  • Numbers are processed locally in your browser, never uploaded — no signup, no install

🔒 Local processing · numbers not uploaded · only structure and checksum are checked

← Back to Global ID Validator

FAQ

Q1Why do some new numbers fail?
Since October 2020 Korea randomized the digits after the 7th, no longer following the old weighted checksum. Numbers issued after that may show as invalid under the traditional mod-11 — this is expected.
Q2Is the number uploaded?
No. All computation runs locally in your browser with JavaScript; the number never leaves your device.
Q3Does a valid result mean it exists?
No — it only means the birth-date structure and check digit fit the old rule; no real identity is looked up.