Key Takeaways
- The "fixed rate method" (67c/hour) includes mobile phone costs.
- If you use the fixed rate method, you don't need a usage log.
- If you claim actual mobile phone costs, a 4-week log is mandatory.
- Claims for small amounts ($50 and under) are generally allowed with simple calculations.
The Short Answer
If you're using the 67 cents-per-hour "Fixed Rate Method" for working from home, you don't need a mobile phone log. The rate already includes your home phone and mobile phone use. However, if you want to claim your actual bills, you'll need one.
Scenario 1: Small Claims ($50 and Under)
If your work-related mobile phone and internet claim is $50 or less, you can generally claim it without an extensive 4-week log. This depends on you being able to justify the small amount if the ATO questions it. A simple calculation (e.g., $10 per month for occasional work calls) is usually accepted.
Scenario 2: Large Claims (Requiring a Log)
If you're claiming more than $50 for your mobile phone and you're not using the fixed rate method, you *must* keep a diary/record of your work and private calls and data usage over a 4-week representative period. This diary must show the percentage of your usage that was specifically work-related.
What about the Phone Hardware?
If you buy a new mobile phone solely for work, you can usually claim the depreciation of the phone's cost. This is separate from the "running costs" (your monthly bill). If the phone costs more than $300, you have to spread the deduction over its useful life (typically 3 to 4 years).
Record Keeping Strategy 2026
For most taxpayers who work from home for part or all of their week, the 67c fixed rate method is the simplest way to get a deduction for phone use without the headache of data logs. If you need to make a larger claim, we recommend using a diary app to track your usage for 28 consecutive days early in the tax year.
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