The FBT logbook, explained
What Fringe Benefits Tax has to do with your work ute, why the ATO asks for twelve weeks, and which parts of it Axlerun does for you.
Can't find this in your app? Your business owner can switch the Logbook module off, which hides it for everyone — there's no message when that happens. An owner or admin can turn it back on in Settings → Business settings → Active Modules.
If your business owns a vehicle that someone can also use privately — driving it home, running an errand in it — that private use is a fringe benefit, and the business may owe Fringe Benefits Tax on it. A logbook is how you show that most of the driving was for work, so you're only taxed on the part that wasn't.
This page is the background. The step-by-step pages either side of it cover the doing.
The two ways to work out the tax
The ATO lets you use either:
- The statutory formula method — a flat percentage of the vehicle's value, no logbook required. Simple, and usually more expensive.
- The operating cost method — you pay on the private-use share of what the vehicle actually cost to run. This is the one that needs a logbook, and for a vehicle that's mostly used for work it's normally the cheaper answer by a wide margin.
Axlerun exists to make the second one practical.
Why twelve weeks
The ATO doesn't ask you to log every trip forever. It asks for a continuous twelve-week period that fairly represents the vehicle's usage for the year. That period then sets the business-use percentage.
For each trip in the period you need the date, the odometer reading at the start and end, the distance, and what the trip was for. You also need the vehicle's odometer reading at the start and end of the whole period.
A logbook kept properly counts for the year you keep it plus the following four — five years in total — unless the vehicle's usage changes materially. Axlerun tracks which FBT years each period you've exported from covers.
The word "representative" is doing a lot of work
This is where logbooks fall over. A twelve-week window is only valid if it reflects the year. Pick your busiest quarter and your business-use percentage will look better than the truth — and that's exactly the kind of period the ATO can disallow, which puts you back on the statutory formula with penalties on top.
Axlerun ranks candidate windows and shows you how far each one sits from the vehicle's full-year figure, so you can pick one you'd be comfortable defending rather than simply the highest number.
What Axlerun does, and what it doesn't
It does: record every trip automatically with route, distance, odometer and time; let you classify trips business or private in bulk or by rule; rank the twelve-week windows worth using; tell you what's missing before you export; and produce the file.
It doesn't: decide what counts as business use, or whether the logbook method is right for your situation. Those are questions for your accountant. Axlerun keeps the evidence — it doesn't give tax advice.
The FBT year runs 1 April to 31 March, not the financial year. When Axlerun asks which FBT year you're working on, it means the year starting on that April date.
Which plan you need
Recording the logbook — automatic GPS trips, manual entries, classification, the Logging Hours schedule — is free on Drive.
Cruise is the working plan. It adds the ATO-ready export, but also the auto-classify rules that put a purpose on recurring trips as they close, and the compliance alerts that keep renewals from lapsing. That ordering matters: a logbook nobody classified all year isn't a finished logbook waiting for an export button, it's a year of trips to sort out first — and the ATO wants a purpose on every business trip.
Choose your 12-week FBT period
Last updated Mon Aug 24