If an expense relates to both income-earning use and private use, you need to apportion (split) it. For example, rates, insurance, internet and power bills, repairs for general wear and tear. Use the following formula to work out how much you can deduct for the expenses that need to be apportioned.
Add up all expenses that need to be apportioned
This is the total amount of expenses you need to apportion between income-earning and private use.
Count the days your asset was used
Include both your income-earning and private use days over the income year.
The combined amount is your asset's total usage.
Divide your income-earning days by total usage
This is your divided amount.
Multiply the total expenses figure by your divided amount
These are your apportioned expenses - the share of your mixed-use expenses that you're allowed to claim.
Add your apportioned expenses to your fully deductible expenses
These are your total deductible expenses. In your tax return you can deduct these expenses from the income you earned from the asset.
Work out expenses for your mixed use assetGo to this tool