Why You Still Need a Logbook – Even if Your Car Is 100% Business Use

by | Jun 4, 2025 | Uncategorized | 0 comments

If you’re using your car entirely for business purposes, you might assume a logbook isn’t necessary. After all, there’s no personal use—so why keep records? Unfortunately, the ATO doesn’t accept assumptions, even when your situation seems straightforward. Here’s why a logbook is still essential, and how it can protect you at tax time.

 

The ATO Requires Evidence

The Australian Taxation Office (ATO) requires written evidence to support any claim for motor vehicle expenses using the logbook method. This includes:

  • The business-use percentage, based on your logbook
  • Odometer readings at the start and end of the year
  • Receipts or records for running costs like fuel, servicing, insurance, and registration

Even if your vehicle is used 100% for business, the ATO needs documentation to support this. Without a logbook, your claim could be reduced or denied in a review or audit.

 

It’s About Substantiating the Claim

Claiming 100% business use raises red flags with the ATO. They’ll want to know:

  • Where is the vehicle kept overnight?
  • Is it available for personal use?
  • How do you prove that every trip is work-related?

A valid logbook over a continuous 12-week period, showing consistent business use, is the best way to demonstrate your case.

 

What the Logbook Needs to Include

Your 12-week logbook must show:

  • Date of each trip
  • Start and end odometer readings
  • Distance travelled
  • Purpose of the journey

If your business use stays consistent, the logbook remains valid for up to five years—as long as your pattern of use doesn’t change.

 

The Benefits of Doing It Right

Having a valid logbook can help you:

  • Maximise your tax deduction
  • Avoid disputes with the ATO

Keep your accountant (and yourself) stress-free at tax time

Tip: Set a Reminder

If you don’t have a current logbook, now’s a good time to start one. It only takes 12 weeks, and the effort pays off with peace of mind and potentially bigger deductions.

Need help setting up a logbook or working out the best method to claim car expenses? Get in touch with our team at Advisory One—we’re here to make tax time easier.