Under the Income Tax Assessment Act 1997, businesses claiming car expenses or providing car fringe benefits must keep car log books and odometer records for at least 5 years. Clock starts: due date for the tax return.
Log books and odometer records that support a car's business-use percentage, for income tax and FBT.
8 provisions in 2 laws apply to these records. Each one is set out below with its own period and start date.
The terms
s 28-150(1)–(3)Income Tax Assessment Act 1997
5 years
The 5 years start on the due day for lodging your income tax return for that latest income year. If you lodge your return later, the 5 years start on the day you lodge it... the retention period is extended if, when the 5 years end, you are involved in a dispute with the Commissioner that relates to a deduction worked out using a business use percentage that you are relying on the log book to support.
s 28-155(2)Income Tax Assessment Act 1997
5 years
you must retain the odometer records for the same period as the log book, and section 28‑150 applies to them in the same way as it applies to the log book
s 28-155(3)Income Tax Assessment Act 1997
5 years
you must retain the odometer records for the same period as written evidence of a car expense for the car for the income year, and section 900‑75 applies to them in the same way as it applies to written evidence of an expense
s 28-100(5)Income Tax Assessment Act 1997
No period stated
Start not stated
s 28-130(4)Income Tax Assessment Act 1997
Until the end of the period for which you must retain the last log book that you began to keep for the original car before the day of effect of the nomination [period from Income Tax Assessment Act 1997 (Cth) s 28-150 Retaining the log book for the retention period]
until the end of the period for which you must retain the last log book that you began to keep for the original car before the day of effect of the nomination
s 123(2)Fringe Benefits Tax Assessment Act 1986
See the provision
statutory evidentiary documents, being log book records or odometer records maintained by or on behalf of the employer
s 10A(a)Fringe Benefits Tax Assessment Act 1986
No period stated
Start not stated
s 65E(a)Fringe Benefits Tax Assessment Act 1986
No period stated
Start not stated
Conditions and exceptions Caution
From the provisions:
- Retention period extended while a relevant dispute with the Commissioner is ongoing
- Applies if you keep a log book for the income year
- Applies if you do not keep a log book for the income year
- Subsections (4)-(6) provide relief where original document lost or destroyed but a substitute exists or reasonable precautions were taken
- Only relevant to obtaining a reduction in operating cost for a log book year of tax
- Must be for an applicable log book period in relation to the car
- Only relevant in a log book year of tax
The law
Income Tax Assessment Act 1997, s 28-150(1)–(3) · Retaining the log book for the retention periodOfficial text ↗
You must retain the log book: (a) first, until the end of the latest income year for which you rely on the log book to support your calculation of the business use percentage for the car; and (b) then for another 5 years.
Text as at 27 August 2026
Income Tax Assessment Act 1997, s 28-155(2) · Retaining odometer recordsOfficial text ↗
If you keep a log book for the income year, you must retain the odometer records for the same period as the log book, and section 28‑150 applies to them in the same way as it applies to the log book.
Text as at 27 August 2026
Income Tax Assessment Act 1997, s 28-155(3) · Retaining odometer recordsOfficial text ↗
If you don't keep a log book for the income year, you must retain the odometer records for the same period as written evidence of a car expense for the car for the income year, and section 900‑75 applies to them in the same way as it applies to written evidence of an expense.
Text as at 27 August 2026
Income Tax Assessment Act 1997, s 28-100(5) · SubstantiationOfficial text ↗
You must retain the log book and the odometer records. Subdivision 28‑I has the rules about this.
Text as at 27 August 2026
Income Tax Assessment Act 1997, s 28-130(4) · Replacing one car with anotherOfficial text ↗
You must retain the nomination document until the end of the period for which you must retain the last log book that you began to keep for the original car before the day of effect of the nomination.
Text as at 27 August 2026
Fringe Benefits Tax Assessment Act 1986, s 123(2) · Retention of statutory evidentiary documentsOfficial text ↗
where an employer fails to retain, for the retention period, statutory evidentiary documents, being log book records or odometer records maintained by or on behalf of the employer, those documents shall be deemed never to have been maintained
Text as at 1 July 2026
Fringe Benefits Tax Assessment Act 1986, s 10A(a) · No reduction of operating cost in a log book year of tax unless log book records and odometer records are maintainedOfficial text ↗
log book records and odometer records are maintained by or on behalf of the provider for an applicable log book period in relation to the car
Text as at 1 July 2026
Fringe Benefits Tax Assessment Act 1986, s 65E(a) · No compliance with substantiation rules in log book year of tax unless log book records and odometer records are maintainedOfficial text ↗
log book records and odometer records have been maintained by or on behalf of the recipient for an applicable log book period in relation to the car
Text as at 1 July 2026
Income Tax Assessment Act 1997s 28-150(1)–(3), s 28-155(2), s 28-155(3), s 28-100(5), s 28-130(4) · Federal Register of Legislation
Legislation ↗Fringe Benefits Tax Assessment Act 1986s 123(2), s 10A(a), s 65E(a) · Federal Register of Legislation
Legislation ↗Australian Taxation OfficeOfficial guidance
Guidance ↗Other terms that apply to these records
This page covers car log books and odometer records on their own. The same file is often caught by other laws as well, with different periods and start dates. See why a legal term is not a schedule.
ScheduleOne
3 records. 3 sets of rules. They don't agree.
One business file can hold all of these at once.
Car log books and odometer records5yIncome Tax Assessment Act 1997, s 28-150(1)–(3), s 28-155(2), s 28-155(3), s 28-100(5), s 28-130(4) · due date for the tax return
Fringe benefits tax records5yFringe Benefits Tax Assessment Act 1986, s 132(1), s 132(2), s 123(1), s 123(3), s 135F · completion of the transactions
Travel and expense substantiation records5yIncome Tax Assessment Act 1997, s 900-25(1)–(3), s 900-75(1)–(2), s 900-90(1)–(3), s 900-20, s 900-85, s 900-165, s 900-170 · due date for the tax return
Now do that for every record your organisation holds, and redo it when the law changes. ScheduleOne has done that work, and keeps it current.
See ScheduleOne →