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CGT Main Residence Exemption: What Sellers Must Prove

The main residence exemption is one of the most valuable tax concessions in Australia, but it depends on evidence of how you actually lived in the property. Here is what to assemble before settlement so the claim holds.

The capital gains tax main residence exemption is the reason most owner-occupiers in Brisbane never pay tax on the gain when they sell their family home. It is also one of the most commonly disputed parts of the tax system, particularly when the seller has owned more than one property, has lived overseas, or has rented the home out at any point during ownership.

This article is not tax advice. It walks through the evidence you should assemble before settlement, the situations that draw closer ATO attention, and the practical questions worth taking to your accountant well before the contract is signed.

⚠️ This is general information. The CGT main residence exemption has multiple sub-rules, transitional provisions, and edge cases. Always work with a registered tax agent or accountant on your specific position before relying on the exemption.

What the exemption actually does

If you are an Australian tax resident and the property you are selling was your main residence for the entire period of ownership, the gain is generally fully exempt from CGT. The land covered is the dwelling itself plus up to two hectares used primarily for private purposes. Only one property at a time can be your main residence, with a six-month overlap window allowed when moving from one main residence to another.

Where ownership spans periods when the home was used differently (rented out, used to produce income, partially used for business), the exemption is generally apportioned. The classic case is the home that was lived in for several years, then rented out, then sold. The "absence rule" can extend the exemption while the home is rented in some circumstances, but not indefinitely.

What "main residence" means in practice

The ATO is not looking at the address on your tax returns alone. It is looking at where you actually lived. The factors typically considered include:

Length of residency. A continuous period of months or years carries far more weight than a few weeks of token occupation.

Personal possessions. Where your furniture, clothing, and everyday belongings were kept. A home that contains only minimal furniture during a claimed occupation period reads as a property held for sale, not a residence.

Mail and official records. Where you received mail, where bank statements and government correspondence were addressed.

Electoral and registration records. Whether the address appeared on the electoral roll, your driver's licence, your vehicle registration.

Utility usage. Whether power, water, and gas accounts were in your name and showed usage patterns consistent with occupation, not minimal stand-by usage.

Family life. Where children attended school, where the family GP was, where social and community connections were anchored.

Any single one of these factors can be explained away. It is the pattern across all of them that establishes whether the claim is supportable.

Situations that draw closer attention

Some scenarios raise the audit risk and are worth understanding before you settle.

Multiple properties owned simultaneously. If you own two or more properties and have not formally nominated one as your main residence, the ATO may scrutinise the claim, especially when both properties have characteristics that could plausibly be the main home.

Short occupation followed by sale. Buying, occupying for a short period, and selling at a gain triggers attention, particularly if the pattern repeats. The ATO has well-established rules about whether such transactions are treated as a main residence sale, an isolated profit-making transaction, or something else.

The home was rented at any point. The exemption may still apply in part or in full under the absence rule, but the calculation becomes more complex and the supporting documentation more important.

Portions of the home were used for business. A dedicated home office, a garage converted to commercial use, or a home-based business that claimed running costs against tax can affect the exemption proportion.

The owner was a foreign resident at any point during ownership. Significant changes to the foreign residency rules in recent years have affected access to the exemption for owners who became non-residents during ownership. This is a high-risk area where professional advice is essential.

The land exceeds two hectares. Properties on larger blocks need a calculation of which two hectares are exempt and how the rest is treated.

Records to assemble before settlement

The practical action item before you sign a contract is to assemble a working file of evidence. The earlier this is done, the better, because some records become harder to retrieve years after the fact.

Council rates notices for each year of claimed residency, addressed to you at the property.

Utility bills (electricity, gas, water, internet) in your name showing consumption patterns consistent with occupation.

Bank statements showing transactions at local merchants, supermarkets, fuel stations, and service providers near the property.

Removalist and storage receipts showing furniture moved into and out of the property.

Insurance policies for contents at the address.

Electoral roll evidence and driver's licence change of address records.

Mail samples from a range of senders (banks, government, professional bodies, subscriptions) showing the property as the postal address.

School enrolment records for any school-aged children during the period claimed.

None of these need to be exhaustive. A representative sample from across the period of claimed residency is usually sufficient. The point is to be able to demonstrate the pattern of life at the address, not to produce every document ever issued.

When the property has been rented at any point

If the home was your main residence and then you moved out and rented it, the absence rule may extend the exemption. As a general principle, while you continue to treat the property as your main residence (and do not nominate another property as your main residence), the exemption can extend for up to six years if the property is producing income, or indefinitely if it is not.

Critically, you can only have one main residence at a time. If you rent the home out, move into a new home, and treat the new home as your main residence, the absence rule on the original property is broken.

This is one of the most commonly misunderstood areas of the exemption. The detail of how the calculation works depends on dates, periods of vacancy or rental, and whether you nominated alternative main residences. This is exactly where an accountant earns their fee.

Practical questions to take to your accountant

Before listing the property for sale, consider taking these questions to your accountant or tax agent:

1. Will the full main residence exemption apply to my expected gain on this sale?

2. Are there any periods during my ownership where the exemption is reduced or apportioned?

3. Have I owned any other properties during this period that could complicate the main residence nomination?

4. Am I currently or have I ever been a foreign tax resident, and how does that affect my position?

5. What records should I be assembling now, before settlement, to support the exemption?

6. What is the estimated tax position if the exemption is partly disallowed, so I know my downside?

Asking these questions early gives time to fix any gaps in evidence and prevents nasty surprises on the next year's tax return.