How to Keep an ATO-Compliant Valid Log Book and Protect Your Tax Claim
If you claim work-related vehicle expenses, either personally or through your business, the ATO expects proper documentation.
A vehicle log book is one of the simplest ways to support your claim. It shows how much of the vehicle’s use is work-related and helps protect you if the ATO reviews your position.
It does not need to be complicated. But it does need to be done correctly. We’ve provided straightforward guidance and an ATO-compliant log book template below to get you started.
When the ATO requires a vehicle log book
Vehicle log book requirements depend on how the vehicle is owned and how the expense is being claimed.
- Claiming personally: You may need a log book to support work-related car expense claims. In some cases, the cents per kilometre method may be a simpler alternative.
- Company vehicles: If a business provides a vehicle and there is private use, Fringe Benefits Tax (FBT) may apply. A log book is required to support the business-use percentage.
The record-keeping rules are largely the same, but the relevant year differs:
- FBT: year ends 31 March
- Income tax: year ends 30 June
If your circumstances are unclear, speak to your adviser as early as possible. It is easier to get the records right during the year than to try to correct them later.
You can also refer to the FAQs below for further guidance.
Why the log book matters
A log book supports the percentage of vehicle use you claim as work-related. That percentage directly affects:
- whether FBT applies (and how much is payable)
- how much can be claimed as a tax deduction
If the ATO reviews your claim and the log book does not support your business-use percentage, your tax position can be adjusted.
If a vehicle is used by a director, owner or key employee, it is worth reviewing the position early, as the tax implications can be significant.
What you need to record
Your vehicle log book must:
- Record at least 12 continuous weeks of travel that reflects your usual travel patterns.
- If your travel patterns change, you may need to start a new log book sooner.
For each work-related trip, record:
- Date of travel
- Start and end locations
- Odometer reading at start and end
- Kilometres travelled
- A clear purpose for the trip. Simply writing “business” is not enough. The purpose needs to be specific.
Keep odometer readings:
- At the start and end of the log book period
- At the start and end of each income tax or FBT year
- To show total kilometres travelled for the year
Without accurate odometer records, the business-use calculation cannot be substantiated.
Multiple vehicles
If more than one vehicle is involved, you may need separate records.
- For income tax claims, if you use the log book method for multiple vehicles, the log book for each vehicle generally needs to cover the same 12-week period.
- For FBT, where a business provides multiple vehicles, a separate log book is required for each vehicle.
If you manage several vehicles across staff, it is worth reviewing your record-keeping systems early to ensure they are practical and meet ATO requirements. If you are unsure whether your systems are appropriate, our advisers can help you set up a compliant and workable approach.
Manual or electronic log books
You can keep records using:
- A pre-printed log book
- Your own spreadsheet or template
- The free vehicle log book template below
- Electronic tools such as the ATO’s myDeductions app or third-party apps.
The ATO app can be convenient, but note that myDeductions may pre-fill amounts into your tax return. Always review the figures carefully before lodging.
If using a third-party app, make sure it captures the required details under tax law.
Download the free vehicle log book template
Good records protect your claim and reduce the risk of problems later.
If you are looking for a simple vehicle log book template that aligns with ATO record-keeping requirements in Australia, this template is designed to capture the key information needed to support your claim.
The template helps you record:
- date and purpose of each trip
- start and end odometer readings
- kilometres travelled
- the information needed to calculate your business-use percentage
Download the free vehicle log book template below to simplify your record keeping and ensure you meet ATO requirements.
If you would like clarity on whether the log book method is right for you, or how FBT applies to your business structure, speak to a Synectic adviser so your records are set up correctly from the start.
Frequently Asked Questions
How long is a log book valid?
Generally, five years, provided your travel pattern does not materially change. If your usage changes significantly, you may need to start a new log book earlier.
Can I claim work-related car expenses without a log book?
Yes, under the cents per kilometre method. This is available to individuals claiming work-related car expenses, including sole traders and partnerships claiming for a car.
It does not require a log book, but it has annual kilometre limits and may not produce the best outcome where business use is high.
When do I need a log book for FBT?
If a business provides a vehicle to an employee, director or associate and there is private use, FBT may apply.
If you are using the operating cost method to calculate the taxable value of the benefit, a valid log book is required to determine the business-use percentage.
Do companies and trusts use the log book method?
For income tax purposes, companies and trusts generally claim vehicle expenses using the actual costs method.
A log book may still be needed to support the business-use percentage, particularly where there is private use or FBT exposure.
What counts as business-use kilometres?
Travel directly connected to earning income. Travel between home and a regular workplace is usually private, unless specific exceptions apply. Seek advice if you think exceptions may apply to you.
How does the business-use percentage work?
Business-use percentage is calculated by dividing business kilometres travelled by total kilometres travelled for the year.
A higher business-use percentage generally increases your income tax deduction and may reduce FBT payable.
Do I need to record personal vehicle use?
You do not need to record private trips, but including them can make your calculations clearer.
Do I need to keep receipts as well as a log book?
Yes. A log book helps establish the business-use percentage, but you still need receipts or other records to substantiate the expenses being claimed (such as fuel, servicing, insurance and registration).
If keeping receipts feels like hard work, or you are not sure what you should be keeping, review your record-keeping approach early in the year to avoid gaps later.
What happens if the log book does not meet ATO requirements?
The ATO may reduce or deny the claim and adjust your tax position. Penalties and interest may apply.
Need guidance?
A compliant vehicle log book provides certainty. It protects your deduction, reduces audit risk and ensures you are not paying more tax than necessary.
If you would like assistance, our team can help you get the record keeping and treatment right from the start.
Contact a Synectic Adviser to get started.
