SEPA Creditor Identifier (CI) Regex for JavaScript

What this pattern does

This page provides a well-structured, multi-part regular expression for matching sepa creditor identifier (ci), 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

// SEPA Creditor Identifier (CI)
// ReDoS-safe | RegexVault — Finance > Bank Identifiers

const sepaCreditorIdentifierCiRegex = /^[A-Z]{2}[0-9]{2}(?:ZZZ|[A-Z]{3})[A-Z0-9]{1,28}$/;

function validateSepaCreditorIdentifierCi(input: string): boolean {
  return sepaCreditorIdentifierCiRegex.test(input);
}

// Example
console.log(validateSepaCreditorIdentifierCi("DE98ZZZ09999999999")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Bank Identifiers 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

Structure: 2-char country code + 2 check digits + 3-char creditor business code (ZZZ if not assigned) + national identifier. Check digits use same MOD-97 algorithm as IBAN.