Maintaining a logbook can be an essential part of managing your tax obligations, especially if you use your personal vehicle for work-related purposes. As an accountant, I regularly advise clients on the importance of keeping a logbook and the specific records required to meet the Australian Taxation Office (ATO) standards. Here’s what you need to know about maintaining a logbook for tax purposes.

1. What is a Logbook?

  • Purpose of a Logbook: A logbook is a record that details the use of your vehicle. It’s used to determine the percentage of vehicle use that is work-related, which in turn affects your claimable expenses on your tax return.
  • Validity Period: Once completed, a logbook is valid for five years, unless there are significant changes in your work-related vehicle use.

2. Starting a Logbook

  • 12 Consecutive Weeks: The ATO requires that your logbook is kept for a minimum continuous period of 12 weeks. This period needs to be representative of your usual travel throughout the year.
  • Beginning Date: You can start your logbook at any time, but it must cover a period when the car is being used for its typical pattern of business use.

3. Information to Record in a Logbook

  • Dates of Travel: Record the start and end dates of the logbook period.
  • Odometer Readings: Note the vehicle’s odometer readings at the start and end of the 12-week period.
  • Each Journey: For each journey, record the date, odometer readings at the start and end, total kilometers traveled, and the reason for the trip (e.g., meeting with a client).
  • Business vs Personal Use: Distinguish between business and personal use.

4. Calculating Business Use Percentage

  • Percentage Calculation: At the end of the 12-week period, calculate the percentage of car use that is for business purposes. This percentage is then applied to car expenses to determine your claimable amount.
  • Expenses Include: Car expenses include fuel, servicing, insurance, interest on loans, depreciation, and lease payments.

5. Importance of Accurate Records

  • ATO Compliance: Accurate logbook records are essential for ATO compliance. Inaccurate or incomplete logbooks can lead to disallowed claims and potential penalties.
  • Record Keeping: Keep your logbook, along with all receipts and records related to car expenses, for five years from the date of your tax return.

6. Using Logbook Apps

  • Digital Logbooks: There are several logbook apps available that can simplify the record-keeping process. These apps can automatically track your trips and calculate your business use percentage.

7. Seeking Professional Advice

  • Our role is to help you understand your obligations regarding logbook records and how to accurately calculate your claimable car expenses.


Maintaining a logbook is a crucial practice for anyone using a personal vehicle for work-related purposes in Australia. It ensures that you can accurately claim vehicle expenses on your tax return and remain compliant with ATO requirements. Remember, keeping accurate and detailed records is key to simplifying your tax affairs and maximising your eligible deductions.