Top Mistakes to Avoid With CGT Property Valuations

Capital gains tax on property sales can be complicated—and errors can mean overpaying tax or triggering ATO audits. Here are the most common mistakes seen with CGT property valuations, and how to avoid them.

1. Not Including All Allowable Improvements

Upgrades like extensions, kitchens, or landscaping directly affect your cost base. Failing to document and include these can result in higher CGT liability. Keep all invoices and photographs for your records.

2. Using a Non-Certified Valuer

Appraisals by agents or unqualified individuals are rarely accepted by auditors. Use a Certified Practising Valuer with API membership for evidence-based, defensible reports. Registered valuers are able to provide an ATO compliant valuation report, ensuring to meet the ATO requirements of using a certified property valuer.

3. Self-Assessing Instead of Professional Valuation

DIY calculations or guesswork often result in missed deductions or calculation errors. Professional valuers ensure every deduction and market nuance is accounted for. A registered valuer can work with your tax professional representative to ensure all details around your property are taken into consideration.

4. Reporting the Wrong Date or Event

CGT valuation dates matter. Some examples are the change-of-use date, inheritance date, or retrospective requirements. Clarify with your accountant and valuer exactly which date the ATO requires.​

A retrospective valuation is a realestate valuation based on a certain date in the past. This can be an ATO requirement and ValueMax registered property valuers can work with your tax professional to ensure the details on your valuation report are correct.

5. Ignoring Depreciation Claimed

If you have claimed depreciation over time, you must reduce your cost base by those amounts. This is a frequent and costly oversight. The ValueMax team work with Quantitive Surveyors who specialise in Tax Depreciation Schedule reports and can refer you to a professional to assist with these requirements.

6. Failing to Keep Proper Records

Poor documentation undermines your valuation’s credibility and risks a denied deduction. Retain all contracts, invoices, and valuation reports securely.

For more details, see How to Order a CGT Valuation for Your Investment Property