Keeping a logbook

If you use the logbook method, you:

  • can claim the business-use percentage of each car expense, based on the logbook records of your car’s usage
  • must keep a logbook so you can work out the percentage
  • must have written evidence of your fuel and oil costs, or odometer readings on which your estimates are based
  • must have written evidence for all your other expenses.


At the end of the income year, Tim’s logbook shows he travelled a total of 11,000 kilometres, of which 6,600 were for business.

To work out the percentage the car was used for business purposes, Tim made the following calculation:

6,600/11,000 × 100 = 60%

Tim's total expenses, including depreciation, are $9,000 for the income year. To work out how much he could claim, Tim completed the following calculation:

$9,000 × 60% = $5,400

End of example

Getting a logbook

You can use pre-printed logbooks (available from stationery suppliers) or make your own.

Valid for five years

Each logbook you keep is valid for five years, but you may start a new logbook at any time.

If you establish your business-use percentage using a logbook from an earlier year, you must keep that logbook and maintain odometer readings in the following years.

Your first year

If this is the first year you have used the logbook method, you must keep a logbook during the income tax year for at least 12 continuous weeks. That 12-week period needs to be representative of your travel throughout the year.

If you started to use your car for business purposes less than 12 weeks before the end of the income year, you can continue to keep a logbook into the next year so it covers the required 12 weeks.

Two or more cars

If you want to use the logbook method for two or more cars, the logbook for each car must cover the same period. The 12-week period you choose should be representative of the business use of all cars.

Information your logbook must contain

Each logbook you keep must contain the following information:

  • when the logbook period begins and ends
  • the car’s odometer readings at the start and end of the logbook period
  • the total number of kilometres the car travelled during the logbook period
  • the number of kilometres travelled for each journey recorded in the logbook (if you made two or more journeys in a row on the same day, you can record them as a single journey). You will need to record the  
    • start and finishing times of the journey
    • odometer readings at the start and end of the journey
    • kilometres travelled
    • reason for the journey.
  • the business-use percentage for the logbook period
  • the odometer readings at the start and end of each income year you use the logbook method
Last modified: 22 Jun 2016QC 33731