International · Validation
Korean resident registration number (RRN) check.
Check the format, birth date and check digit of a 13-digit South Korean resident registration number (주민등록번호), and decode the century and sex digit. Format and checksum only.
How it works: multiply the first 12 digits by the weights 2, 3, 4, 5, 6, 7, 8, 9, 2, 3, 4, 5, add them up, and take (11 − sum mod 11) mod 10. That must equal digit 13. Digits 1–6 are YYMMDD; digit 7 gives the century and sex.
Inputs
Result
Enter a number and press Check.
How the resident registration number is built
The RRN (주민등록번호) is a 13-digit number, written YYMMDD-GXXXXXX: a date of birth, one digit for century and sex, six more digits, and one check digit. Foreign residents receive an alien registration number that follows the same pattern.
| Digit 7 | Born | Sex | Holder |
|---|---|---|---|
| 9 / 0 | 1800–1899 | Male / Female | Korean citizen |
| 1 / 2 | 1900–1999 | Male / Female | Korean citizen |
| 3 / 4 | 2000–2099 | Male / Female | Korean citizen |
| 5 / 6 | 1900–1999 | Male / Female | Foreign resident |
| 7 / 8 | 2000–2099 | Male / Female | Foreign resident |
Check digit: weights 2, 3, 4, 5, 6, 7, 8, 9, 2, 3, 4, 5 on the first twelve digits; the check digit is (11 − (sum mod 11)) mod 10, so a result of 10 becomes 0 and 11 becomes 1. python-stdnum’s own example: 971013-9019902 has weighted sum 207, 207 mod 11 = 9, and 11 − 9 = 2, matching the final digit.
A failed check is not proof of invalidity
Since October 2020, newly assigned numbers no longer encode the region of registration, and the check digit may not apply to newer numbers. A number that fails this checksum can still be genuine. A number that passes is only well-formed.
Format and checksum only — not a registry lookup
This page checks format and checksum only. It cannot confirm that a number was ever issued or that it belongs to anyone; only the Korean government can do that.
Sources
- python-stdnum, stdnum/kr/rrn.py (weights, check digit, century mapping)
- Korean Wikipedia, 주민등록번호 (formula, digit 7 table, October 2020 change)
Privacy and scope
A resident registration number is sensitive personal data. This tool runs entirely in your browser: nothing you type is transmitted, stored, or logged, and it checks format and checksum only, with no query to any Korean government system. Do not enter numbers belonging to other people that you have no reason to hold.