Pattern

Regex for Korean RRN

13-digit Resident Registration Number, formatted with hyphen.

The Korean RRN regex is ^\d{6}-[1-8]\d{6}$ — copy it below, or open it in the explainer for a token-by-token breakdown.

The pattern

^\d{6}-[1-8]\d{6}$

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What it matches

900101-1234567
050505-3456789
991231-2123456

What it doesn't match

900101-9234567
9001011234567
900101-12345678

Notes & gotchas

Korean RRN: 6-digit DOB (YYMMDD) + hyphen + 1 digit indicating gender/century (1/2=1900s male/female, 3/4=2000s male/female, 5/6=foreigner 1900s, 7/8=foreigner 2000s) + 6 digits.

Code in your language

Use the explainer's Code tab to generate ready-to-paste snippets in JavaScript, Python, Java, .NET, Go, Ruby, and PHP for this pattern.

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Token-by-token breakdown

Every part of the pattern, left to right:

Token	Meaning
`^`	start of string (or line in multiline mode)
`\d{6}`	exactly 6 times: digit (0–9)
`-`	literal text “-”
`[1-8]`	any of: 1–8
`\d{6}`	exactly 6 times: digit (0–9)
`$`	end of string (or line in multiline mode)

About this pattern

Country-specific identifier formats vary widely. The pattern below validates structure; many real IDs include checksums that regex can't verify. For high-stakes use, validate against the issuing authority.

Quick usage in different languages

This exact pattern — with the correct escaping and idioms for each language:

JavaScript: /^\d{6}-[1-8]\d{6}$/.test(value)
Python: re.match(r"^\d{6}-[1-8]\d{6}$", value)
Java: Pattern.compile("^\\d{6}-[1-8]\\d{6}$").matcher(value).matches()
C# / .NET: Regex.IsMatch(value, @"^\d{6}-[1-8]\d{6}$")
Go: regexp.MustCompile(`^\d{6}-[1-8]\d{6}$`).MatchString(value)
Ruby: /^\d{6}-[1-8]\d{6}$/.match?(value)
PHP: preg_match('~^\d{6}-[1-8]\d{6}$~', $value)

The explainer’s Code tab regenerates these for any pattern you paste, and the downloadable cheat sheet bundles the breakdown, all seven snippets, and the pitfalls below onto one printable page.

Common pitfalls

Anchored to the whole string. This pattern uses ^ and $, so it requires the entire input to match. To find it inside a longer text, drop the anchors and use the global (g) flag.
Escape it correctly per language. In Java and JavaScript strings each backslash must be doubled (\\d); in Python, Go, and C# use raw/verbatim strings so the backslashes survive.
Validate beyond format. Matching the format doesn't guarantee the value is real. Confirm the korean rrn against a source of truth (database, API, or checksum) where it matters.

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