Answer
The most common reason why an employee is being overtaxed is an incorrect Tax File Number. Lightning Payroll uses an Australian Tax File Number validation system which is checked in real-time by simply entering a TFN into an employee’s Tax Rates screen. If the TFN displays in green, it is valid. If the number shows up in red, it is invalid (seen below).
If you find the TFN you’ve been given is invalid please ask your employee to verify their correct TFN.
See here for more information on temporary TFNs.