Korean Postal Code (5-digit, post-2015) Regex for Go

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching korean postal code (5-digit, post-2015), ported and verified for Go. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Go project — whether you're validating in a Gin handler, a gRPC service, or a command-line tool.

Go Implementation

// Korean Postal Code (5-digit, post-2015)
// ReDoS-safe | RegexVault — Localization > Postal Codes

package validation

import "regexp"

var koreanPostalCode5digitPost2015Re = regexp.MustCompile(`^[0-9]{5}$`)

func ValidateKoreanPostalCode5digitPost2015(s string) bool {
    return koreanPostalCode5digitPost2015Re.MatchString(s)
}

// Example
// fmt.Println(ValidateKoreanPostalCode5digitPost2015("03000")) // true

Test Cases

When to use this pattern

This pattern is drawn from the Localization > Postal Codes category and carries a ReDoS-safe certification. That matters for Go developers because Go's RE2 engine is inherently safe from catastrophic backtracking, but this pattern has been additionally verified for correctness. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

South Korea switched from the old 6-digit format (XXX-XXX) to a new 5-digit system in August 2015. The old format is no longer valid for new addresses. North Korea is not covered by this system.