Why Is My Employee's Tax File Number Showing As Invalid?

Lightning Payroll checks every Tax File Number as it is typed, using the Australian Taxation Office's own check-digit formula. A TFN shown as invalid has failed that check, which means the digits entered are not a valid TFN.

The check is reliable, so an invalid TFN almost always comes down to a transcription error rather than a fault in the program. One mistyped or transposed digit is enough to fail it, even though the number can look correct at a glance.

What To Check

1. Compare the number digit by digit against the employee's own ATO record. Reading it back one digit at a time catches transpositions that the eye skips over.
2. Make sure only digits have been entered. A TFN is 8 or 9 digits, with no spaces, dashes or letters.
3. Confirm the number is a Tax File Number and not another ATO reference such as an ABN or a superannuation member number.
4. If the employee read the number out or sent a photo, ask them to confirm it against a written ATO document.

If the number still fails after all of that, ask the employee to confirm their TFN directly with the ATO. Lightning Payroll cannot accept a number that does not pass the ATO check.

If The Employee Does Not Have A TFN Yet

You do not need to wait for the real number before running a pay. The ATO publishes standard codes for employees who have not yet supplied a TFN, and Lightning Payroll accepts them. See What Do I Do If My Employee Has No Tax File Number?