Keeping a Logbook for Work-related Car Expenses

Under the Logbook Method, your claim is based on the business use percentage of the expenses for the car.

Car expenses include fuel, repairs, registration, insurance and decline in value but not capital costs, such as the purchase price of your car, the principal on any money borrowed to buy it and any improvement costs.

You can claim fuel and oil costs based on either your actual receipts or you can estimate the expenses based on odometer records that show readings from the start and the end of the period you had the car during the year.  You need written evidence for all other expenses for the car.

Your business use percentage is the percentage of kilometres you travelled in the car for work during the year divided by the total kilometres travelled by the car during the year.  To calculate the business use percentage, work out the total kilometres travelled during the logbook period and how many of these were business kilometres. Divide the business kilometres by the total kilometres travelled. This is your business use percentage.

If the pattern of your car use changed during the year, make a reasonable estimate of your business use percentage for the whole of the year, taking into account your logbook, odometer and other records, any variations in the pattern of use of your car and any changes in the number of cars you used in the course of earning your income.

Logbook period

Your logbook is valid for five years. You must have kept a logbook during the first year that you want to claim car expenses under this method. The log book must cover at least 12 continuous weeks. If you started using your car for work-related purposes less than 12 weeks before the end of the year, you can extend the 12-week period into the following income year. (If you are using the logbook method for two or more cars, the logbook for each car must cover the same period.)

If you established your business use percentage using a logbook from an earlier year, you need to keep that logbook and maintain odometer records.

Your logbook must show:

  • when the logbook period starts and ends, and the odometer readings at these times
  • the total number of kilometres the car travelled during the logbook period
  • the number of kilometres travelled for work during the logbook period based on the journeys recorded for the period
  • the business use percentage for the period.

Entries in the logbook for each business trip must be made at the end of the journey (or as soon as possible afterwards) and show the:

  • date the journey began and ended
  • odometer readings at the start and end of the journey
  • kilometres travelled on the journey
  • reason for the journey.
  • Your records must also show the make, model, engine capacity and registration number of the car.