Australia TFN Generator
Online generator for Tax File Number (TFN) issued by the Australian Taxation Office (ATO) for payroll and tax testing.
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About the Australian Tax File Number (TFN)
The Tax File Number (TFN) is an exclusive 9-digit tax identifier issued by the Australian Taxation Office (ATO) to individuals, businesses, and superannuation funds.
It is required for employment in Australia, filing income tax returns, opening bank accounts without maximum withholding tax, and tracking retirement pensions.
TFN Calculation and Validation Algorithm (Weighted Modulo 11)
The official Australian Taxation Office (ATO) algorithm applies positional weights and modulo 11 division:
Sum = d₁ × 1 + d₂ × 4 + d₃ × 3 + d₄ × 7 + d₅ × 5 + d₆ × 8 + d₇ × 6 + d₈ × 9 + d₉ × 10; Valid if Sum mod 11 = 0
- Extract all 9 digits of the TFN.
- Multiply each digit by its corresponding positional weight [1, 4, 3, 7, 5, 8, 6, 9, 10].
- Sum all 9 resulting products together.
- The TFN is mathematically valid if the total sum is an exact multiple of 11 (remainder 0).