A car logbook lets you claim the work or business share of everything your car actually costs: fuel, insurance, registration, servicing, interest and depreciation. It needs 12 continuous weeks of trip records, odometer readings and receipts, and one logbook covers five years. Most logbooks we see fail on the same few points, and every one of them is avoidable.
Keep the logbook and odometer records for five years after the last year you rely on them. With two or more cars, keep a logbook for each over the same period.
Each entry should be made at the end of the trip, or as soon as possible afterwards. The test is whether someone else could read it and see why the trip was work.
| Date | Odometer start | Odometer end | Km | Destination and purpose | |
|---|---|---|---|---|---|
| ✓ | 4 Aug | 48,210 | 48,262 | 52 | Office to Smith & Co, 14 Albany Hwy: quarterly review meeting, then back to office |
| ✓ | 5 Aug | 48,301 | 48,318 | 17 | Site A to site B, Canning Vale: deliver tiles and inspect install |
| ✗ | 6 Aug | 40 | Work | ||
| ✗ | 7 Aug | 48,330 | 48,371 | 41 | Home to office (regular workplace) |
The third entry has no odometer readings and no destination or purpose. The fourth is ordinary home-to-work travel, which is private and cannot be counted.
Each has strict conditions. Check with us before counting these trips.
Without a logbook you can claim 91 cents for each work kilometre in 2026–27, up to 5,000 km per car, with no receipts but a record of how you worked out the kilometres. A logbook usually wins when the car is expensive to run or you drive a lot for work.
Rebuilt from memory or a calendar at tax time. Entries need to be made at the end of each trip or soon after; a reconstructed logbook is not a logbook.
Twelve weeks chosen over a busy period, or including a holiday when the car sat in the garage. The period must reflect how the car is used across the year.
The most common error. Ordinary trips between home and a regular workplace are private, even for shift workers and people with long drives.
No reading at the start or end of the 12 weeks, or at 1 July and 30 June in later years. Without them the percentage cannot be applied.
Still relying on a logbook from before a job change, a move or a new car, or more than five years old.
“Work”, “meeting” or “site”. Each entry needs the destination and why the trip was work.
A perfect logbook only supports the percentage. The costs it applies to still need receipts and records, including how depreciation was worked out.
Where more than one car is claimed, each needs its own logbook covering the same 12 weeks.
Claiming costs reimbursed by an employer, paid through a novated lease or salary packaging, or on a car the employer provides.
The ATO publishes a two-page summary for small business, Motor vehicle expenses (PDF), and the myDeductions tool in the ATO app includes a car logbook.
At least 12 continuous weeks, representative of your travel. One logbook then supports your claim for five years, as long as your pattern of use doesn’t change. Keep it for five years after the last year you rely on it.
The date, odometer readings at the start and end of the trip, kilometres travelled, the destination and the reason for the trip. You also need odometer readings at the start and end of the 12-week period.
Generally not. Trips between home and your regular workplace are private, even for shift work, long distances or when there is no public transport. Limited exceptions apply for bulky tools, itinerant work and where home is a base of employment.
It depends on what the car costs and how much of its use is for work. Cents per kilometre is 91 cents a kilometre in 2026–27, capped at 5,000 km. A logbook usually gives more for an expensive car or high work use, and is the only option above 5,000 work kilometres.
Yes. The myDeductions tool in the ATO app includes a logbook, and other apps are acceptable if they record the same details. Add the purpose of each trip promptly.
Yes, if the old logbook no longer represents how you use the car. A new job, a new home, a change of role or territory, or a different car usually means starting a new 12-week logbook.
Law from 1 July 2027. Split your gain at 30 June 2027, compare a valuation with the Government formula and see the tax against the old rules.
Model your gain → TrustsProposed from 1 July 2028. Build your family group, compare a wage with distributions and test the opt-out election.
Model your family group → ReadBoth changes explained in one place, with a worked case study, the options for each trust and short answers to client questions.
Read it → WorkersFrom 2026–27, an automatic deduction with no receipts. See whether claiming your own expenses would give you more back.
Check your options → CarsThe 12-week rule, what each trip needs, where logbooks fail, and whether a logbook beats 91 cents a kilometre.
Read and compare → TalkBring your summary to a consultation with a Porters CA Chartered Accountant in South Perth or Albany.
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