TFN Generator

Generate Australian Tax File Numbers (TFN) with valid checksum

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About Australian Tax File Numbers (TFN)

A Tax File Number (TFN) is a 9-digit number issued by the Australian Taxation Office (ATO). This generator creates valid TFN format numbers with proper checksum validation for testing and educational purposes.

The ninth digit is a check digit: multiply the nine digits by the weights 1, 4, 3, 7, 5, 8, 6, 9 and 10, and the total divides evenly by 11. Nine random digits fail that test about ten times out of eleven, which is why placeholder data like 123456789 gets rejected by payroll systems and onboarding forms. Every number here passes, so your validation code sees the same shape it will see in production.

Checking a number rather than making one? The TFN validator runs the same arithmetic in reverse.

Disclaimer

Important: Generated numbers are NOT real Tax File Numbers issued by the ATO and have NO legal validity. They are for testing and educational purposes only.

Prohibited Uses: You must NOT use generated TFNs for:

  • Actual tax filing or tax-related purposes
  • Identity verification or authentication
  • Business registration or official transactions
  • Any fraudulent or illegal activity

Legal Consequences: Misuse of generated TFNs may result in:

  • Criminal prosecution under Tax Administration Act 1953 and Criminal Code Act 1995
  • Investigation by the Australian Taxation Office (ATO)
  • Civil liability, fines, and/or imprisonment

Your Responsibility: By using this tool, you acknowledge that you understand these risks and agree to use it only for legitimate testing purposes. You are solely responsible for any misuse of generated numbers.