Selling an Investment Property in Australia: Here's How Much CGT You Could Legally Avoid and the Window Most Australians Miss

Selling an investment property in Australia is one of the largest financial transactions most people will ever make. It is also, in most cases, the event where the largest avoidable tax bill is generated.

The reason: the strategies that reduce CGT on a property sale have hard cutoffs. Most of them close the moment you sign the contract. The investors who do their tax planning after accepting an offer — which is almost everyone — have already lost access to the strategies worth tens of thousands of dollars.

This guide covers the full picture: what CGT on the sale of an investment property actually costs in 2026, the window that closes at exchange, what you can still do after exchange, and the strategies most investors never implement in time.

Capital gains tax on the sale of a residential investment property is not a flat rate. It is your marginal income tax rate applied to the discounted capital gain — and the discount rate changed in 2026.

Under current law, individuals who have held the property for more than 12 months receive a 33% discount on the capital gain before it is added to their assessable income. This is down from the 50% discount that applied before the 2026 budget.

What that means in practice on a $500,000 capital gain:

Under old rules (50% discount): $250,000 added to income. At 47% marginal rate: $117,500 CGT.
Under new rules (33% discount): $335,000 added to income. At 47% marginal rate: $157,450 CGT.
Difference: $39,950 more tax on the same gain.

On a $300,000 gain — realistic for a property held 8 to 12 years in most markets — the additional tax under the new rules at the top marginal rate is approximately $24,000. On a $700,000 gain, it approaches $56,000.

This is the baseline. Every strategy below works to reduce the taxable gain, the rate applied, or both. For the full breakdown by income level: CGT on investment property Australia: what you will actually pay in 2026.

The date that matters for CGT is the date of the contract of sale, not the settlement date. The financial year in which you sign contracts is the year in which the capital gain is assessed. This creates a hard cutoff for several of the most valuable CGT strategies.

What you can no longer do after exchange:

Change the financial year. If you sign contracts on 28 June, the gain falls in the current financial year. If you sign on 3 July, it falls in the next. The difference in tax — if your income is significantly lower in one year than the other — can be tens of thousands of dollars. Once you sign, the year is set.

Crystallise capital losses. If you hold other investments sitting at a loss, selling them in the same financial year as the property reduces your net capital gain dollar for dollar. This coordination must happen before 30 June of the same year as the property contract. After exchange, you cannot retroactively change which year the gain falls in to align with existing losses.

Restructure ownership. If you wanted the sale to occur via an SMSF in pension phase (zero CGT) rather than in personal name (30% effective rate), the property had to be inside the SMSF structure before the sale. A restructure after exchange is not possible.

Apply the main residence exemption to new periods. If the 6-year main residence rule applies, the exemption period is fixed at the time of the sale decision. You cannot extend it after signing.

This is the most powerful and most commonly missed strategy. If you are selling in a year when your income is lower than usual — the year you retire, the year you go on parental leave, the year a business winds down — timing the contract to fall in that year can reduce the marginal rate applied to the gain by 10 to 15 percentage points.

On a $400,000 capital gain (discounted to $268,000 at 33%), the difference between 47% and 32.5% marginal rate is approximately $38,500 in tax. That saving is available simply by choosing when to sign. It requires planning the sale 6 to 18 months in advance — not 6 minutes before you call an agent.

The practical trigger: if you know your income will drop significantly in any of the next 3 years, that is almost certainly the optimal year to sell any investment property with a large unrealised gain. Modelling this before you decide when to sell costs almost nothing. Not modelling it can cost $30,000 to $50,000.

If you lived in the property as your principal residence before renting it out, and you have not nominated another property as your main residence during that period, you may be able to treat the property as your main residence for CGT purposes for up to 6 years after you moved out.

If you sell within that 6-year window, the entire gain may be exempt from CGT regardless of the discount change, regardless of your marginal rate, regardless of anything else. Zero tax on a $500,000 gain if the exemption applies in full.

If you sell after the 6-year period, the exemption applies proportionally — the gain is split between the exempt period and the taxable period, and only the taxable portion is assessed. Even a partial exemption covering 4 of 10 years of ownership reduces the taxable gain by 40%.

Before listing any property you once lived in, have a tax adviser determine whether this exemption applies, for how long, and what it is worth. Many investors do not ask this question until after the sale, at which point it is too late.

Your capital gain is the sale price minus the cost base. A higher cost base means a smaller gain. This strategy is available right up to the point of settlement — not just before exchange.

The cost base of an investment property includes: purchase price; stamp duty and legal fees at purchase; loan establishment fees if not previously deducted; building and pest inspection at purchase; capital improvements during ownership (extensions, structural renovations, new appliances — not repairs); and selling costs including agent commissions, legal fees, and advertising.

Many investors underestimate their cost base by $20,000 to $50,000 because they have not kept records of every capital expenditure. Receipts for a kitchen renovation completed 8 years ago are still valid cost base components. They reduce the gain dollar for dollar.

One important note: depreciation deductions claimed during ownership reduce the cost base for Division 43 (capital works) claims made after 1999. Your accountant needs the full depreciation schedule to calculate the adjusted cost base correctly. If you have been claiming depreciation and your accountant does not ask about this, that is a problem worth raising.

Capital losses from other assets realised in the same financial year as the property sale reduce the net capital gain before the discount and marginal rate apply. A $50,000 capital loss from shares sold in the same year reduces a $400,000 property gain to $350,000 — saving approximately $15,000 in tax at the top marginal rate.

This requires forward planning: knowing which other assets are sitting at a loss, deciding whether those losses are worth crystallising (versus holding in expectation of recovery), and timing the disposals to fall in the same financial year as the property contract.

The most effective version of this strategy combines it with the financial year timing strategy above: if you are selling the property in a low-income year to get a lower marginal rate, you also crystallise any available losses in that same year to further reduce the net assessable gain.

If the property is held inside a self-managed super fund and the fund has transitioned to pension phase, the CGT on sale is zero. Not reduced. Zero.

This is unchanged by the 2026 budget. The CGT discount change applies only to personal holdings. The pension phase exemption inside an SMSF remains legislated and intact.

On a $500,000 capital gain, the difference between selling personally (effective rate 30% under 2026 rules at top marginal rate) and selling through an SMSF in pension phase (0%) is $157,450. This is not a strategy for the faint-hearted — it requires the property to have been inside the SMSF structure from purchase, and the fund needs to have transitioned to pension phase before the sale contract is signed.

But for investors who set up their SMSF correctly, held property inside it, and are now approaching or in retirement, this is the most powerful CGT strategy available in Australia. For the complete SMSF property framework: why high earners are rushing into SMSF property after the 2026 budget.

Once the contract is signed and exchanged, the most powerful strategies are locked out. But several important actions remain available up to and including settlement:

Complete your cost base documentation. Gather every receipt for purchase costs, capital improvements, and selling costs before settlement. Your accountant needs these to calculate the correct gain.

Ensure depreciation records are complete. If you have been claiming depreciation, make sure your quantity surveyor and accountant both have the complete schedule. The depreciation claimed during ownership affects your cost base.

Review your withholding obligations. If the property sold for $750,000 or more, the purchaser is required to withhold 12.5% of the purchase price and remit it to the ATO unless you provide a clearance certificate. Apply for the clearance certificate well before settlement — it takes up to 28 days.

Consider your instalment obligations. If you pay PAYG instalments, your accountant may need to vary them in the year of sale to account for the additional tax liability from the capital gain. Not doing this can result in a large tax bill at year end with no planning for it.

The window is the 12 to 24 months before you intend to sell. That is when all of the strategies above are available. That is when the financial year can be chosen, the SMSF structure reviewed, the capital losses identified, and the cost base documented fully.

Most Australian property investors do their CGT planning in the months after they accept an offer. By then, the financial year is set, the losses cannot be coordinated retroactively, the structure cannot be changed, and the exemption periods are fixed.

The investors who pay significantly less CGT than the average are almost never smarter about tax law. They are simply earlier. They thought about the tax consequences of the sale before they started thinking about the sale price, before they called an agent, before they put a date in their calendar.

On a property with a $400,000 gain, the difference between planning and not planning — in terms of legally available tax reduction — is typically $30,000 to $70,000. The planning itself costs almost nothing. A conversation with a tax adviser. An afternoon reviewing records. A decision about timing.

For the full set of strategies and what each is worth in dollar terms: how to avoid CGT when selling investment property: 7 strategies before you sign. And for what the 2026 rules changed: why the CGT discount cut is costing property investors $40,000 per sale.

Book a Strategy Call

If you are planning to sell an investment property in the next 1 to 3 years, book a call before you appoint an agent. The decisions you make in the months before signing matter more than anything that happens after.

Book a free 20-minute strategy call at: https://www.ausretirementoffice.com.au/book

Disclaimer: The information provided by Australian Retirement Office is general in nature and educational only. It does not constitute financial product advice, legal advice, or taxation advice, and does not take into account your objectives, financial situation, or needs. Australian Retirement Office does not hold an Australian Financial Services Licence (AFSL). Where appropriate, we may refer you to licensed professionals within our partner network. We may receive referral fees for these introductions. All investments carry risk, including potential loss of capital. Past performance is not a reliable indicator of future returns. You should obtain professional advice and review all relevant Product Disclosure Statements (PDS) before making any financial decisions.

Related reading: CGT on Investment Property: What You Will Pay in 2026 | How to Avoid CGT When Selling: 7 Strategies | The CGT Discount Is Gone: What to Do Before 2027 | SMSF Property: Zero CGT in Pension Phase | Investment Property Depreciation: Cost Base Impact