Selling a rental property can be a significant financial event — and it often comes with tax implications that many investors need help navigating. The Australian Taxation Office (ATO) has clear rules on how capital gains tax (CGT) applies when you sell a rental property, and understanding these can help you plan effectively and avoid costly surprises.
At Roy A McDonald Pty Ltd Accountants Doncaster, we regularly assist property owners with CGT planning and compliance. Here’s an update on what the ATO expects and how CGT works when you sell your investment property.

What Is Capital Gains Tax (CGT)?
When you sell a rental property for more than what it cost you to acquire and hold — including improvements and associated expenses — the profit you make is considered a capital gain and is generally subject to CGT.
This applies to properties acquired after 20 September 1985, when CGT was introduced, meaning nearly all modern rental property investments fall under these rules.

How CGT Is Calculated on Rental Properties
The basic concept is straightforward:
- Determine your cost base. This includes what you paid for the property plus associated costs such as purchase fees, stamp duty, legal fees, and selling costs.
- Subtract deductible amounts such as depreciation and capital works claimed over the years.
- Calculate the gain. The difference between your sale proceeds and your adjusted cost base is your capital gain — the amount added to your taxable income.
If the rental was owned for more than 12 months, many individual taxpayers qualify for a 50 % CGT discount, meaning only half the gain is included in your assessable income.
Timing Matters
Under ATO rules, the CGT event is triggered when you enter into a contract to sell the property, not when the sale is settled in the future.
This is important because the year in which you contract to sell determines the tax return in which you must include your capital gain.
Main Residence Considerations
If the property was ever your main residence before it became a rental, you might be eligible for a partial main residence exemption.
That can reduce the CGT payable by excluding part of the gain that relates to the time you lived in the property as your home. In some cases — such as when a rental property becomes your home — clients can apply a part-exemption based on the proportion of time it was your residence versus rented out.
Record-Keeping Is Essential
The ATO expects you to keep detailed records to support your CGT calculation. This includes:
- Purchase documentation and costs
- Records of capital improvements
- Depreciation and capital works claimed
- Selling costs such as agent and legal fees
Without accurate records, you may miss deductions or miscalculate your cost base — potentially increasing your tax liability.
Capital Losses Can Help
If you make a capital loss when selling — that is, the sale proceeds are less than your cost base — you can carry that loss forward and deduct it from future capital gains. This can be an effective tax planning tool for investors with multiple CGT assets.
Foreign Owner Withholding Rules
If you’re a foreign resident seller (or selling to a foreign resident), additional ATO rules such as foreign resident capital gains withholding may apply, meaning the buyer may need to withhold part of the sale price to cover potential tax liabilities.
Plan Ahead for CGT
CGT isn’t just a compliance obligation — it’s a key part of investment planning. Decisions about when to sell, how long to hold a property, and whether to claim certain deductions can materially affect your overall return after tax.
At Roy A McDonald Pty Ltd Accountants Doncaster, we help property investors understand CGT obligations, prepare accurate calculations, and plan tax-effective strategies tailored to individual circumstances.
If you’re considering selling a rental property or want to review your CGT exposure, contact our team today for expert advice and personalised support.
Source: www.ato.gov.au


