Car and Vehicle Expense Claims: Logbook vs Cents Per KM
Choose the right method to maximise your motor vehicle deductions
Here is a number that should grab your attention: Australian workers using the wrong car expense claim method are leaving an average of $2,100 on the table every year. With the ATO receiving data directly from fuel cards, toll accounts, and registration authorities, they know you are driving for work. The question is whether you are claiming everything you are entitled to.
If you use your personal vehicle for work purposes, you have two methods to calculate your deduction: the cents per kilometre method at 85 cents per km (2024-25 rate), or the logbook method based on your actual expenses. Choosing incorrectly could cost you thousands, or worse, trigger an audit if your claims do not match reality.
The Real Problem: One Size Does Not Fit All
The ATO offers two methods because different drivers have vastly different circumstances. A sales representative driving 40,000 business kilometres per year has completely different needs than an office worker who occasionally visits clients.
Yet most Australians default to the cents per kilometre method simply because it seems easier. While simplicity has value, this lazy approach costs high-kilometre drivers significant money. Conversely, some taxpayers invest hours maintaining detailed logbooks when the simpler method would actually give them a bigger deduction.
The confusion deepens when you consider:
- The cents per kilometre method is capped at 5,000 kilometres per year, giving a maximum deduction of just $4,250
- The logbook method has no kilometre cap but requires meticulous record-keeping
- Choosing the wrong method is not just about money. Inadequate records can trigger ATO scrutiny
- You cannot switch methods mid-year, so getting it right from July matters
Let us break down exactly when each method works best, and how to implement them correctly.
Why So Many Drivers Get This Wrong
The fundamental issue is that most people do not understand what each method actually covers, or they dramatically underestimate their business kilometres.
Hook: Think you only drive 5,000 business kms? You are probably wrong.
When the ATO asks taxpayers to estimate their business kilometres, most grossly underestimate. A nurse who visits patients, a tradie driving between jobs, or a professional attending client meetings often drives double or triple what they initially guess.
Consider what counts as work-related travel:
- Travel between two separate workplaces
- Travel from your workplace to a client or customer location
- Travel to attend work conferences, meetings, or training
- Travel to collect supplies or equipment for work
- Travel by trades people, sales reps, and medical professionals between jobs
What does not count: travel from home to your regular workplace (that is commuting, not work travel).
Many taxpayers unknowingly limit their claim to 5,000 km when they actually drive 15,000 or even 30,000 business kilometres. Under the logbook method, those extra kilometres translate to real deductions.
Solution Framework: Choosing Your Method
Hook: The 5,000 kilometre question that determines everything
The decision tree is simpler than most people think. Ask yourself one question: Do I drive more than 5,000 business kilometres per year?
If your answer is NO (under 5,000 km): Use Cents Per Kilometre
The cents per kilometre method at 85 cents per km (2024-25 rate) is ideal for:
- Office workers with occasional client visits
- Employees who primarily work from one location
- Anyone who wants minimal record-keeping
- People whose car expenses are relatively low (fuel-efficient vehicles, low running costs)
Records required: A reasonable estimate of business kilometres (diary entries, calendar records) showing how you calculated 5,000 km or less.
Maximum deduction: 5,000 km x $0.85 = $4,250
If your answer is YES (over 5,000 km): Consider the Logbook Method
The logbook method is powerful for:
- Sales representatives, medical professionals, trades workers
- Anyone with significant travel between work locations
- Drivers with higher running costs (larger vehicles, frequent servicing)
- Workers willing to invest time in proper record-keeping
Records required: A valid 12-week logbook plus receipts for all vehicle expenses.
Maximum deduction: No cap. Based on your actual business percentage of actual costs.
Step-by-Step: Implementing Each Method
Hook: The 12-week logbook that pays dividends for five years
Here is the beautiful thing about the logbook method: you only need to complete a 12-week logbook once every five years, provided your circumstances remain similar. That investment of 12 weeks opens up potentially massive deductions for five full financial years.
Creating a Valid Logbook
Your logbook must run for a continuous 12-week period and record:
- Start and end odometer readings for every single trip (business and personal)
- Date of each trip
- Purpose of the trip (client meeting, site visit, supply run)
- Start and end locations
- Kilometres travelled
- Business percentage calculated at the end
At the end of 12 weeks, calculate your business use percentage. If you drove 6,000 total kilometres and 4,200 were for business, your business percentage is 70 percent. This percentage applies to ALL your car expenses for the year.
Expenses You Can Claim Under Logbook
With a 70 percent business use percentage, you claim 70 percent of:
- Fuel and oil
- Registration
- Insurance
- Repairs and servicing
- Tyres
- Interest on a car loan
- Depreciation (or lease payments)
Real Numbers: The Difference Can Be Staggering
Hook: Same driver, same car, $5,800 difference in deductions
Let us compare both methods for Rebecca, a pharmaceutical sales rep who drives extensively:
Rebecca's Situation:
- Total kilometres driven: 45,000
- Business kilometres: 36,000 (80 percent business use)
- Annual fuel costs: $6,500
- Registration: $850
- Insurance: $1,400
- Servicing and repairs: $1,800
- Depreciation on vehicle: $5,500
- Total running costs: $16,050
Cents Per Kilometre Method:
Maximum 5,000 km x $0.85 = $4,250 deduction
Logbook Method:
$16,050 x 80 percent business use = $12,840 deduction
Difference: $8,590 in additional deductions
At a 32.5 percent marginal tax rate, that is an extra $2,792 in Rebecca's pocket. At the 37 percent rate, it is $3,178. This is not aggressive tax planning. It is simply choosing the correct method for her circumstances.
But What About Lower-Kilometre Drivers?
Now consider David, an accountant who occasionally visits clients:
David's Situation:
- Total kilometres driven: 12,000
- Business kilometres: 3,000 (25 percent business use)
- Annual running costs: $8,000
Cents Per Kilometre Method:
3,000 km x $0.85 = $2,550 deduction
Logbook Method:
$8,000 x 25 percent = $2,000 deduction
For David, the simpler cents per kilometre method actually gives a $550 higher deduction with far less paperwork. This illustrates why the choice matters.
Critical Mistakes That Trigger ATO Audits
Hook: Three words that make auditors reach for your file
The phrase "5,000 kilometres - unrestricted logbook" appears on thousands of tax returns each year. It is a red flag. If you claim exactly 5,000 km year after year without any supporting records, expect questions.
Mistake 1: Claiming travel that is actually commuting
Travel from home to your regular place of work is commuting, not a work expense. Even if you check emails in the car or take work calls, it does not transform your commute into a business trip. The ATO specifically targets this overclaim.
Mistake 2: Invalid or incomplete logbooks
Your logbook must record EVERY trip, not just business trips. If you only log work travel, the ATO cannot calculate your business percentage, making the entire logbook invalid.
Mistake 3: Outdated logbooks
That logbook from 2018 is no longer valid. You need a new one every five years, or sooner if your circumstances change significantly (new job, moved house, different travel patterns).
Mistake 4: Claiming expenses without receipts
Under the logbook method, you need actual receipts for fuel, servicing, and other expenses. Bank statements alone may not be sufficient. The ATO wants to see itemised receipts for major claims.
How TaxBot Makes Vehicle Claims Effortless
TaxBot transforms the traditionally painful logbook process into something you barely have to think about:
- Automatic Trip Detection: GPS tracking identifies when you are driving and automatically logs trips. Just confirm whether each trip was business or personal
- 12-Week Logbook Generator: TaxBot creates an ATO-compliant logbook with all required details, formatted and ready for audit
- Real-Time Method Comparison: See exactly how much you would claim under each method, updated as you drive
- Receipt Capture: Snap photos of fuel receipts, service invoices, and insurance documents. Optical character recognition extracts the details
- Annual Summary Report: Export a complete record of your vehicle expenses and business use percentage
TaxBot users who switch from cents per kilometre to a properly documented logbook method claim an average of $4,100 more in vehicle deductions. The app essentially pays for itself hundreds of times over.
Take Action: Which Method Is Right For You?
The 2024-25 financial year is underway. If you have not started tracking your vehicle use, now is the time. Here is your action plan:
- Estimate your annual business kilometres. Be honest and thorough about what qualifies
- If over 5,000 km, start a logbook immediately. You need 12 consecutive weeks before you can claim under this method
- Download TaxBot to automate your tracking and never worry about missing a trip or losing a receipt
- Keep every receipt for fuel, servicing, registration, and insurance
- Review quarterly to ensure you are on track for maximum deductions
Your car is working hard for you. Make sure you are claiming everything it entitles you to.