How to Keep an ATO-Compliant Logbook (Without It Taking Over Your Life)

A logbook is one of the simplest tax records to get right - and one of the easiest to get wrong, usually because it's started with good intentions in week one and abandoned by week four.

What "compliant" actually means

The ATO expects a logbook to cover 12 continuous weeks, chosen from a period that's genuinely representative of your travel across the year - not your quietest month, and not your busiest. For every trip during that window, you need the date, the odometer reading at the start and end of the trip, the total kilometres, and whether it was business or private. For business trips, the purpose needs to be specific enough to mean something to someone reviewing it later - "site visit, Smith Street project" holds up; "work stuff" doesn't.

You also need odometer readings at the very start and very end of the 12-week period, and - separately - receipts or other evidence for your actual running costs across the full year: fuel, servicing, insurance, registration, interest on a car loan, and depreciation.

The rule that trips people up most

Entries have to be made at the time of the trip, or as close to it as practical. A logbook filled in retrospectively from memory isn't a logbook - it's a guess with a template. If you're ever asked to substantiate it, the ATO can and does check plausibility against things like service records and rego renewal odometer readings.

The upside: five years of mileage

Once you've done the 12 weeks properly, the business-use percentage it produces is valid for up to five years, provided your travel pattern stays roughly the same. Buy a new car, change jobs, or start working from a different location regularly, and you'll need a fresh 12-week logbook - but otherwise, one good logging period covers you for years.

Habits that make it stick

The logbooks that actually get finished are the ones logged trip-by-trip, not reconstructed later. That usually means logging immediately after each drive, using odometer readings rather than estimated distances (estimates are the first thing that falls apart under review), and keeping business and private trips equally diligent - a logbook with only business trips recorded looks exactly like what it is.

Where Odomly fits in

Odomly is built around exactly this workflow: log a trip in seconds with start and end odometer photos, a purpose, and whether it's business or personal. Because every entry is timestamped and photo-verified, your 12-week logbook builds itself as you actually drive, rather than as a task you owe yourself in June. At the end of the period, Odomly turns it into an ATO-compliant report you can hand straight to your accountant.

This article is general information, not tax advice. Confirm current logbook requirements at ato.gov.au or with a registered tax agent.