Spanish Código Postal Regex for Go

What this pattern does

This page provides a well-structured, multi-part regular expression for matching spanish código postal, 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

// Spanish Código Postal
// ReDoS-safe | RegexVault — Localization > Postal Codes

package validation

import "regexp"

var spanishCdigoPostalRe = regexp.MustCompile(`^(0[1-9]|[1-4][0-9]|5[0-2])[0-9]{3}$`)

func ValidateSpanishCdigoPostal(s string) bool {
    return spanishCdigoPostalRe.MatchString(s)
}

// Example
// fmt.Println(ValidateSpanishCdigoPostal("28001")) // 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

Spanish province codes 01-52. Madrid is 28, Barcelona is 08. Ceuta is 51, Melilla is 52. The Canary Islands (Gran Canaria 35, Tenerife 38) are Spanish territory.