ISO 20022 Message Type Regex for Go

What this pattern does

This page provides a well-structured, multi-part regular expression for matching iso 20022 message type, ported and verified for Go. Financial data validation has zero tolerance for false negatives — a missed invalid entry can corrupt downstream calculations. 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

// ISO 20022 Message Type
// ReDoS-safe | RegexVault — Finance > Financial Formats

package validation

import "regexp"

var iso20022MessageTypeRe = regexp.MustCompile(`^[a-z]{4}\.[0-9]{3}\.[0-9]{3}\.[0-9]{2}$`)

func ValidateIso20022MessageType(s string) bool {
    return iso20022MessageTypeRe.MatchString(s)
}

// Example
// fmt.Println(ValidateIso20022MessageType("pacs.008.001.08")) // true

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Financial Formats 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

ISO 20022 message ID: 4-char business area (pacs=payments clearing, pain=payment initiation, camt=cash management, sese=settlement) + 3-digit message number + 001 (version) + 2-digit variant.