ATO Logbook Method 2026-27: 12-Week Rules and When It Beats 91c/km

Quick Answer: ATO Logbook Method (Australia)

The ATO logbook method is the higher-effort car expense method. It can be worth it when your work driving or vehicle costs are high enough that the capped cents per kilometre method leaves money on the table.

To use it, you keep a logbook for a continuous period of at least 12 weeks, work out your business-use percentage, and apply that percentage to your eligible car expenses.

As checked on July 8, 2026, the ATO guidance still states that:

• a valid logbook can be used for up to 5 income years (if your circumstances stay representative)
• you must keep required odometer and expense records
• you can choose between logbook and cents per kilometre each year for the same car, but only one method applies for that claim
• the cents per kilometre rate is 91c/km for 2026-27, up from 88c/km for 2025-26

For 2026-27, the cents per kilometre method tops out at $4,550 per car. The logbook method can beat that when your actual eligible car expenses multiplied by your business-use percentage is higher than $4,550.

Track and classify trips automatically with DriveLog

ATO Car Expense Methods: Logbook vs Cents per Kilometre

The ATO allows 2 methods for a car you own or lease:

1. Cents per kilometre
2. Logbook method

Cents per kilometre (quick summary)

The cents per kilometre method is simple, but it has a cap of 5,000 work-related km per car per income year.

Income year	Cents per kilometre rate	Maximum at 5,000 km
2025-26	88c/km	$4,400
2026-27	91c/km	$4,550

If you are lodging a 2025-26 return, use 88c/km. If you are tracking trips from July 1, 2026 for the 2026-27 income year, use 91c/km. For the full rate update, read our ATO cents per kilometre rate 2026-27 guide or use the ATO cents per km calculator to test the capped method.

Logbook method (quick summary)

The logbook method has more record-keeping, but no fixed 5,000 km cap. You claim the business-use share of your actual eligible car expenses.

Method	Usually better when	Key limit/rule
Cents per kilometre	Your work driving is modest and you want lower admin	Max 5,000 work-related km per car
Logbook method	Your work driving or annual vehicle costs are high	Must maintain compliant logbook + expense records

When the Logbook Method Usually Wins

The logbook method is worth serious consideration when one or more of these apply:

• you regularly exceed 5,000 work-related km
• you have high total annual car costs (fuel, servicing, insurance, registration, decline in value)
• your business-use percentage is strong and consistent
• you can maintain accurate records across the year

If your travel is occasional and record-keeping discipline is low, cents per kilometre may still be the safer option. The logbook method only helps if the records are strong enough to support the claim.

Quick Break-Even Check

For 2026-27, the cents per kilometre cap is:

5,000 km x $0.91 = $4,550

That means the logbook method has to produce more than $4,550 to beat the capped cents per kilometre result.

Use this quick test:

Break-even business-use percentage = $4,550 / total eligible car expenses

Examples:

Annual eligible car expenses	Business-use percentage needed to beat $4,550
$8,000	56.9%
$10,000	45.5%
$12,400	36.7%
$15,000	30.3%

This is only a screening calculation, not a final deduction. It tells you whether a 12-week logbook is likely worth the effort.

ATO Logbook Requirements (What You Must Record)

For a compliant logbook period, the ATO requires specific trip details and odometer evidence.

1. Keep a continuous 12-week representative logbook

Your logbook period must run for at least 12 continuous weeks and represent your normal business-use pattern.

2. Record trip-level details during that period

For each journey in the logbook period, record:

• destination
• purpose of the journey
• odometer at trip start
• odometer at trip end
• kilometres travelled

3. Record odometer readings at required checkpoints

You should have:

• odometer reading at the start and end of the logbook period
• odometer readings for the start and end of the full period you claim for the income year

4. Keep evidence of car expenses

For the logbook method, keep records/receipts (or accepted estimate records where relevant) for expenses such as:

• fuel and oil
• servicing and repairs
• insurance
• registration
• lease payments (if applicable)
• interest (if applicable)
• decline in value and purchase records

5. Know how long the logbook remains valid

A compliant logbook can be valid for up to 5 years if your usage pattern remains representative. If circumstances change materially (for example job role, work location, or travel pattern), you should complete a new 12-week logbook.

How to Calculate Your Deduction With the Logbook Method

The calculation framework is straightforward:

Deduction = Total eligible car expenses x Business-use percentage

Your business-use percentage comes from the logbook period.

Worked example (2026-27)

• Total eligible annual car expenses: AUD 12,400
• Business-use percentage from logbook: 64%
• Deduction: 12,400 x 0.64 = AUD 7,936

Compare with cents per kilometre

If that same driver used cents per kilometre and had 8,000 business km, the method would still cap at 5,000 km:

• 5,000 x AUD 0.91 = AUD 4,550 for 2026-27

In this example, the logbook method yields a larger claim because business travel and annual costs are both substantial. For a 2025-26 return, the cents per kilometre comparison would be 5,000 x AUD 0.88 = AUD 4,400.

Step-by-Step Setup Checklist (First 30 Minutes)

Use this setup sequence so your first 12-week period is easier to defend later.

1. Pick a start date that reflects normal work activity.
2. Confirm which vehicle is being claimed and whether ownership/lease requirements are satisfied.
3. Capture opening odometer reading.
4. Record every work trip during the 12-week window.
5. Keep fuel and expense evidence from day one.
6. Capture closing odometer reading at end of the period.
7. Calculate business-use percentage and store it with supporting records.
8. Continue annual odometer start/end captures for each year you rely on the logbook.

Common Mistakes That Trigger Problems

Most claim issues are avoidable. The common failure points are:

• incomplete trip purpose notes (for example, “meeting” without client/site context)
• gaps in the 12-week period
• forgetting yearly start/end odometer records
• using an old logbook after major role/location change
• poor evidence for expense totals and decline in value

A good standard is that another person (accountant or reviewer) can reproduce your business-use percentage and annual claim from your records without assumptions.

How DriveLog Helps With a 12-Week Logbook

The hard part of the logbook method is not the formula. It is keeping a complete, representative trip record while normal work is happening.

DriveLog helps by giving you one place to:

• capture trips as they happen
• classify work and private driving
• add trip purpose notes while the reason is still fresh
• keep vehicle and odometer context together
• review trips weekly during the 12-week period
• export records when you or your accountant need to calculate the claim

For logbook users, the best workflow is simple: start the 12-week period deliberately, check classifications every few days, and fix missing trip details while you still remember them. Waiting until tax time is where most weak logbooks become hard to repair.

ATO Sources and Last-Checked Dates

The core guidance for this article comes from ATO pages checked on July 8, 2026:

• Expenses for a car you own or lease
• Logbook method
• D1 work-related car expenses 2026 instructions
• ATO Cents per Kilometre Deduction Rate for Car Expenses 2026 Determination
• Records you need to keep

FAQ: AU Logbook Method

How long does an ATO logbook stay valid?

Generally up to 5 income years, as long as it remains representative of your work-related use pattern.

Does the ATO logbook method require exactly 12 weeks?

It requires at least 12 continuous weeks. Longer is fine, but shorter is not compliant for establishing the representative pattern.

Can I switch between logbook and cents per km each year?

Yes. The ATO allows method changes for the same car across different income years. For any one claim period, apply one method correctly with its required records.

What if I change jobs or move and my driving pattern changes?

You should start a new 12-week logbook if the old one is no longer representative.

Do I still need odometer readings after the 12-week period?

Yes. You still need required odometer records for the claim period, including start and end readings for the full period you claim.

Is cents per kilometre still 88 cents?

For 2025-26, yes: the rate is 88c/km. For 2026-27, the official rate is 91c/km from July 1, 2026.

When does the logbook method beat cents per kilometre?

For 2026-27, the logbook method beats cents per kilometre when your eligible car expenses multiplied by your business-use percentage is more than $4,550 per car.

Final Takeaway

For many Australian taxpayers, the logbook method is more work up front but can produce a materially better deduction when business travel volume is high. The edge comes from disciplined record-keeping: representative 12-week data, complete odometer checkpoints, and full expense evidence.

If you want to reduce admin while keeping a claim-ready record trail, use a digital workflow and review your data monthly rather than waiting until tax time. If you are still deciding between methods, compare this guide with our broader ATO cents per kilometre guide.

Start your DriveLog tracking workflow on iPhone