Income Tax Assessment Act 1997
You can choose only one method for all the *car expenses for the *car for the income year. Choosing one method precludes the other method.
However, you can change your choice for the income year.
You choose the " log book " method and deduct $1,000. On audit, the Commissioner finds that your claim is too high and should be reduced to $500. You would have been able to deduct $700 if you had chosen the " cents per kilometre " method. This rule lets you change your choice and deduct the $700.
You can also choose different methods for the same *car for different income years and different methods for different cars for the same year.