1. Why You Only Get One TFN

• Lifetime Identity: Your TFN is linked to your biometrics and Digital ID. It does not change if you change jobs, move states, or change your name.
• The ATO “Super-Computer”: In 2026, the ATO’s automated systems instantly flag duplicate applications by matching your passport number, birth date, and address.
• The “Two Jobs” Myth: You do not need a second TFN for a second job. You simply provide the same TFN to every employer you work for.

2. The Legal Risks & Penalties

If the ATO detects that you are intentionally using two TFNs to split your income and stay under the tax-free threshold or visa work limits:

• Fines: Administrative penalties for “false or misleading statements” can reach thousands of dollars in 2026.
• Visa Cancellation: For international students, “Character Concerns” and “Tax Fraud” are grounds for immediate visa cancellation under the Migration Act.
• Criminal Prosecution: In extreme cases of identity fraud, you could face a prison sentence of up to 10 years.

3. What to Do if You Accidentally Have Two

Sometimes students accidentally apply twice (e.g., if they forgot they had a TFN from a working holiday years ago). If this is you, fix it before they find it:

1. Call the ATO: Contact the Client Identity Support Centre on 1800 467 033.
2. Request a Merger: Be honest and explain that you have two numbers by mistake. The ATO will “cancel” one and merge all records into the correct active number.
3. Update Employers: Once you have the confirmed single TFN, update your details with all current employers to ensure your Single Touch Payroll (STP) data is consistent.

4. 2026 Comparison: TFN vs. ABN