PayTek has just been updated to include the new working holidaymaker tax regime. (This is the new backpacker tax.)
This was introduced effective January 1, 2017.
Essentially you register with the ATO so they know you employ backpackers with the correct visa. You can then tax them at a flat 15% rather than 32.5% if you are not registered.
The taxing calculation is different to the normal tax scales in that it applies the tax rate on a cumulative basis. Once the employee has earned $37 000 in a year you must tax them at 32.5%.
PayTek therefore looks at their earnings for the year and applies the correct rate to their payment.
Click this link for more information ATO working holidaymaker tax