The Australian property investment 6 year rule allows homeowners to treat a former principal place of residence as CGT-exempt for up to six years after moving out and renting it, provided specific ATO conditions are met. This rule can eliminate or significantly reduce capital gains tax when the property is sold, but it does not exempt rental income from tax and must be applied carefully to avoid costly compliance errors.
What Is the Property Investment 6 Year Rule?
The 6 year rule is an Australian Capital Gains Tax provision that allows a property to remain fully CGT-exempt for up to six years after it stops being your main residence and is used to produce income. The exemption applies if the property was your principal place of residence before being rented and you do not nominate another property as your main residence during the same period.
From a tax perspective, the Australian Taxation Office treats the property as if you never moved out during the nominated six-year period. If the property is sold within that timeframe, any capital gain accrued during those years is disregarded for CGT purposes.
Importantly, the rule does not automatically apply. It is claimed at the time of sale through your tax return, not when the property is first rented. This distinction is critical for investors who assume the exemption is “locked in” once the property becomes a rental.
Who Can Use the 6 Year Rule and Under What Conditions?
To qualify for the 6 year rule, the property must have been established as your main residence before it was rented out. This generally requires that you lived in the property, moved personal belongings in, and used it as your primary home rather than an investment from day one.
Once you move out, you may rent the property immediately or leave it vacant for a period. The six-year countdown only applies to periods where the property is producing income. If the property is not rented, the main residence exemption can continue indefinitely until income-producing use begins.
A key restriction is that you can only have one main residence for CGT purposes at any given time. If you buy another home and nominate it as your main residence, the 6 year rule for the former property generally stops from that point, unless you choose to apply the rule strategically to one property only.
| Requirement | ATO Interpretation |
|---|---|
| Prior main residence | The property must have been your principal place of residence before renting. |
| Income-producing use | The six-year limit applies only while the property is rented or available for rent. |
| Single main residence rule | You cannot claim full CGT exemption on two properties at the same time. |
| Claimed on sale | The exemption is applied when the property is sold, not annually. |
How Rental Income Is Taxed While Using the 6 Year Rule
The 6 year rule does not provide any exemption for rental income. All rent received during the period the property is leased must be declared as assessable income in your annual tax return, regardless of whether the property remains CGT-exempt.
Property investors can still claim allowable deductions against that rental income, including interest on investment loans, property management fees, maintenance costs, insurance, and depreciation where applicable. These deductions are assessed independently from the CGT treatment of the property.
This separation often causes confusion. A property can be fully CGT-exempt under the 6 year rule while still generating taxable rental income and deductions each year. The ATO treats income tax and capital gains tax as entirely separate calculations.
Failing to declare rental income correctly while assuming the 6 year rule “covers everything” is a common compliance risk and a frequent trigger for ATO audits in property investment cases.
What Happens When You Sell a Property Under the 6 Year Rule?
If you sell a former main residence within six years of it being rented, and you have not nominated another property as your main residence during that period, the capital gain on sale is generally fully exempt from CGT. The ATO treats the property as if it remained your principal place of residence for the entire ownership period.
If the property is sold after the six-year limit has been exceeded, CGT is applied on a proportional basis. Only the period beyond the six years where the property was income-producing becomes taxable, rather than the entire ownership period.
The CGT event occurs at the contract date, not settlement. This timing matters if the six-year threshold is close, as signing a contract even one day after the six-year mark can affect the taxable portion of the gain.
How Capital Gains Tax Is Calculated If the 6 Year Rule Is Partially Exceeded
When the 6 year rule is exceeded, capital gains tax is calculated based on the proportion of time the property was not covered by the main residence exemption. The ATO uses a time-based apportionment method rather than taxing the full capital gain.
The calculation typically starts from the date the property first produced income after the six-year exemption period ends, not from the original purchase date. A market valuation at the time the exemption ends is often required to determine the correct cost base.
| Scenario | Outcome |
|---|---|
| Rented for 5 years, then sold | 100% CGT exemption applies |
| Rented for 8 years, then sold | CGT applies to 2 years of ownership only |
| Rented for 10 years | CGT applies to years 7–10 proportionally |
Investors may also be eligible for the 50% CGT discount if the property was held for more than 12 months and the owner is an individual or trust, further reducing the taxable amount.
How to Choose Between Two Properties as Your Main Residence
The 6 year rule becomes strategically important when you own more than one property. You can only nominate one property as your main residence for CGT purposes at any given time, but you can choose which property receives the exemption when you sell.
This choice is not made annually. Instead, it is decided retrospectively when a CGT event occurs. Investors often compare which property has experienced higher capital growth and apply the main residence exemption to that asset to minimise overall tax exposure.
However, once the exemption is applied to one property for a specific period, the other property becomes partially taxable for that same timeframe. This trade-off should be modelled carefully, particularly where large value differences exist.
Common 6 Year Rule Mistakes That Trigger ATO Issues
One of the most frequent mistakes is assuming the 6 year rule resets automatically if you move back into the property. While moving back in can reset the exemption period, the conditions must be met and documented, including genuine re-establishment as a main residence.
Another common error is failing to obtain a professional market valuation when required. Without a defensible valuation at the relevant date, the ATO may challenge the cost base used for CGT calculations.
Investors also incorrectly assume that short-term rentals or leaving a property “available for rent” without tenants does not count as income-producing use. The ATO considers availability for rent sufficient to trigger the six-year countdown.
Does the 6 Year Rule Reset If You Move Back In?
Yes, the 6 year rule can reset if you move back into the property and genuinely re-establish it as your main residence. When this occurs, the prior six-year income-producing period ends, and a new exemption period can begin if the property is later rented out again.
To reset the rule, the ATO expects evidence that the property was actually lived in as your primary home. This includes occupying the property for a reasonable period, changing your address on official records, and using the property as your central place of living rather than temporarily or nominally.
Simply staying in the property briefly or leaving it furnished without clear residential intent is unlikely to satisfy ATO scrutiny. The reset relies on substance, not form, and should be supported by documentation.
ATO Record-Keeping Requirements for the 6 Year Rule
Accurate records are essential when applying the 6 year rule, as the exemption is assessed at the time of sale and may relate to events that occurred many years earlier. The ATO places the burden of proof on the taxpayer to substantiate eligibility.
Key records include purchase and sale contracts, evidence of occupancy, rental agreements, loan statements, and records of periods when the property was rented or available for rent. Market valuations are particularly important if the property becomes partially taxable after the exemption period ends.
Without adequate records, the ATO may default to a less favourable CGT outcome. Maintaining a clear timeline of use from acquisition to sale significantly reduces dispute risk.
Strategic Planning Considerations Before Selling
The 6 year rule is most effective when integrated into broader property and tax planning. Timing the sale within the exemption window, modelling capital growth across multiple properties, and understanding the interaction with the CGT discount can materially change outcomes.
For some investors, selling before the six-year limit expires may produce a better after-tax result than holding the property longer. For others, applying the exemption to the higher-growth property and accepting partial CGT elsewhere may be more efficient.
These decisions should be made before contracts are exchanged, as CGT outcomes are locked in at contract date and cannot be altered retrospectively.
Frequently Asked Questions
Can I use the 6 year rule if I never lived in the property?
No. The property must have been your main residence before it was rented. Investment-only properties do not qualify for the 6 year rule.
Does the 6 year rule apply per owner or per property?
The rule applies per property, but is limited by the rule that you can only have one main residence for CGT purposes at any given time.
Is rental income tax-free under the 6 year rule?
No. All rental income must be declared and taxed in the year it is earned, regardless of CGT treatment.
What happens if I sell after more than six years?
Capital gains tax applies proportionally to the period beyond the six-year exemption, not to the entire ownership period.
Do I need a valuation to apply the 6 year rule?
A valuation is not always required, but it is essential when the property becomes partially taxable or when the exemption period ends.
Key Takeaways
- CGT exemption window: The 6 year rule can fully exempt capital gains if conditions are met and the property is sold in time.
- Rental income is taxable: The rule does not affect how rental income is assessed.
- Only one main residence: Strategic nomination is required when multiple properties are owned.
- Timing is critical: CGT outcomes are determined at contract date, not settlement.
- Records matter: Strong documentation is essential to defend the exemption.
References
- Australian Taxation Office — Main residence exemption and absence rule guidance.
- Income Tax Assessment Act 1997 (Cth), Part 3-1 and Part 3-3.
- ATO Capital Gains Tax Guide for Individuals.
