SWIFT Message Type Regex for JavaScript

What this pattern does

This page provides a well-structured, multi-part regular expression for matching swift message type, ported and verified for JavaScript. 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 JavaScript project — whether you're validating in an Express middleware, a Next.js API route, or a client-side form.

Javascript Implementation

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

const swiftMessageTypeRegex = /^MT(?:0[0-9]{2}|[1-9][0-9]{2})$/;

function validateSwiftMessageType(input: string): boolean {
  return swiftMessageTypeRegex.test(input);
}

// Example
console.log(validateSwiftMessageType("MT103")); // 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 JavaScript developers because especially critical in long-running Node.js event loops where a ReDoS vulnerability can block the entire process. 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

Common SWIFT messages: MT103=customer credit transfer, MT202=bank transfer, MT700=LC issuance, MT940=statement, MT950=confirmation. Category 1=customer payments, 2=bank transfers, 7=documentary, 9=statements.