Logbook method
Claiming the business percentage of all your actual car costs, based on a twelve-week logbook.
The logbook method requires you to record every trip for a continuous twelve-week period, noting dates, odometer readings, kilometres and purpose. That establishes your business use percentage.
You then apply that percentage to all actual running costs for the year — fuel, servicing, insurance, registration, interest and depreciation — producing the deduction.
A logbook remains valid for five years provided your usage pattern does not change materially, so the effort is a one-off investment rather than an annual chore.
Keep the logbook alongside evidence of actual costs. The percentage is only half the calculation, and without fuel receipts, servicing invoices and registration records, the business percentage has nothing to be applied to.
Why it beats the cap
With 60% business use and $14,000 of annual running costs including depreciation, the deduction is $8,400 — nearly double the $4,400 cap under cents per kilometre.
The bit people get wrong
The logbook must cover a continuous twelve weeks that genuinely represents your usual travel. A logbook kept during an unusually busy period will not survive scrutiny if your normal pattern is quieter.
Common questions
How long does a logbook last?
Five years, provided your circumstances and usage pattern remain broadly the same. A change of job or role generally requires a new one.
What must each entry record?
The date, start and end odometer readings, kilometres travelled and the purpose of the trip. Vague descriptions such as 'business' are not sufficient.
Can I claim depreciation on the car?
Yes, at your business use percentage, subject to the car cost limit which caps the value on which depreciation can be claimed.
Run your own numbers