Why the capital gains tax discount is back in the firing line

Australia's most hotly contested tax break is back under the microscope: the 50% capital gains tax (CGT) discount.

A Greens-led Senate inquiry, established in November and due to report by March, has reopened the debate, drawing sharply divided submissions from across the housing, finance and community sectors.

Fuel has been added by new figures from the Parliamentary Budget Office, which estimate the CGT discount will cost the budget $247 billion over the next decade.

The same analysis suggests the richest 1% of Australians will receive about 59% of the benefit this year, while people under 35 receive roughly 4%.

With Labor's housing agenda under pressure and affordability worsening, scrutiny is mounting on Treasurer Jim Chalmers ahead of the May Budget.

So, what exactly is the CGT discount, and why are calls to wind it back growing louder?

What is the capital gains tax discount?

Like negative gearing, CGT is most often discussed in a property context, but it applies to assets more broadly, including shares.

Capital gains tax is simply the tax you pay on the profit made when you sell an asset. Any net gain is added to your taxable income and taxed at your marginal rate. Your main residence is generally exempt.

Under current rules, Australian residents who hold an asset for at least 12 months can halve the taxable gain using the 50% CGT discount. Complying superannuation funds receive a one-third discount, while companies receive none.

Take a simple example. An investor buys a property for $600,000 and sells it 18 months later for $750,000. The capital gain is $150,000.

Because the asset was held for more than a year, only $75,000 is added to taxable income (ignoring other costs for simplicity).

CGT discount: How we got here

Australia introduced CGT in 1985 to broaden the tax base and close loopholes that allowed long-held gains to escape tax altogether.

Before the discount existed, the system relied on indexation (stripping out inflation) and an averaging rule to soften the impact of large, one-off gains landing in a single tax year.

While fair in theory, it was complex to administer, requiring costs to be indexed quarter by quarter.

In 1999, the Howard government scrapped indexation for new assets and introduced the flat 50% discount, arguing it would simplify the system and encourage investment.

Who wants what - and why?

With the inquiry open, submissions have poured in from industry groups, renters' advocates, economists and unions. Agreement is scarce.

Industry groups: keep it

Property and construction peak bodies argue the CGT discount is being blamed for problems it didn't create.

Master Builders Australia, the Property Council of Australia and the Real Estate Institute of Australia warn that cutting the discount would deter investors, reduce new housing supply and ultimately worsen rental affordability by reducing rental stock.

The Property Investment Professionals of Australia (PIPA) adds that policy uncertainty is already unsettling landlords.

Its 2025 Investor Sentiment Survey found 35% of investors would stop investing if the discount were cut to 25%, while 16.7% sold at least one property in the past year.

Not everyone agrees. The Planning Institute of Australia argues the discount reinforces speculative behaviour, contributes to spatial inequality and works against well-located housing supply.

Renters' advocates: scale it back

Groups such as Better Renting and the Tenants' Union of NSW want the discount reduced or removed for investment properties, with savings redirected to social and affordable housing.

They argue the CGT discount, when paired with negative gearing, encourages highly leveraged churn, pushing up prices while increasing instability for tenants.

Community organisations: reduce and reinvest

Housing and welfare groups - including the Council to Homeless Persons, Q Shelter, HAAG, Vinnies and ACOSS - support reducing the discount and recycling the revenue into social housing and rent assistance.

Their central argument is equity: the gains are heavily skewed toward higher-wealth households.
The Abundant Housing Network Australia agrees there's a strong tax and budget case for reform, but cautions that CGT changes alone won't fix affordability.

Research from the Grattan Institute suggests trimming the discount would reduce house prices by less than 1%, while planning reform and allowing more homes in established areas would have a far larger impact on prices and rents.

Unions: targeted cuts

The Australian Council of Trade Unions supports reducing the discount to 25% beyond one investment property and limiting negative gearing to a single property, with proceeds used to co-fund public housing and improve rental energy efficiency.

Politics: lines hardening

NSW Treasury has even urged Canberra to rethink the discount, arguing it boosts investor purchasing power and disadvantages first-home buyers.

The Coalition has signalled it would oppose changes, though an AFR report suggests some within the party are urging caution.

Greens senators Nick McKim and Barbara Pocock, who initiated the inquiry, argue the discount overwhelmingly benefits wealthy investors, worsens affordability and undermines tax fairness.

They want it scrapped and the savings invested directly in social and affordable housing.

The bottom line

The fault line is clear.

Builders and real estate groups say: don't touch the discount and fix supply.

Renters' advocates, social services and many economists say: trim a tax break that fuels investor demand... and build more homes.

Whether the Senate committee recommends a middle ground, such as cutting the discount to 25%, grandfathering existing investments, or limiting concessions to new builds, is now the question to be answered in March.

And whether the government listens to those suggestions will be answered in May.

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