indian-financial-utils/src/validators/gstin.ts

Validate PAN, Aadhaar, GSTIN, IFSC, PIN codes and mobile numbers — essential financial identifiers in India.

export function isValidGSTIN(gstin: string): boolean {
  const gstinRegex =
    /^[0-9]{2}[A-Z]{5}[0-9]{4}[A-Z]{1}[1-9A-Z]{1}Z[0-9A-Z]{1}$/;
  return gstinRegex.test(gstin.toUpperCase());
}