Australia's 2025–26 tax receipts came in $4.6 billion above the estimate made in the May Budget, helping reduce the underlying cash deficit to $22.3 billion.

The Final Budget Outcome for 2025–26 shows the deficit was $6 billion smaller than the $28.3 billion forecast in the 2026–27 Budget. Lower-than-expected payments also contributed to the improvement.

The composition of the revenue increase is notable because stronger superannuation fund and investment income collections, rather than higher mining profits or stronger wage taxation, were the main drivers of the better-than-expected tax result.

The $22.3 Billion Deficit in Numbers

The underlying cash deficit for the year ended 30 June 2026 was $22.3 billion, equal to about 0.8% of GDP.

That compares with the $28.3 billion deficit forecast in the May 2026 Budget.

Tax receipts were $4.6 billion above the Budget estimate, while government payments were $1.4 billion lower than forecast.

Together, those movements account for the approximately $6 billion improvement in the final budget position.

Gross debt also finished the year below the May estimate, with the final outcome showing debt $10.6 billion lower than previously forecast.

Where the Extra Tax Revenue Came From

The stronger tax result was driven mainly by higher-than-expected collections associated with superannuation funds and investment income.

The final outcome specifically attributes the $4.6 billion tax receipt upgrade to stronger collections in these areas.

Mining profits, by contrast, came in below expectations.

The improvement was also not primarily driven by additional tax on wages and salaries.

This makes the revenue composition different from periods when commodity prices or employment income were the main sources of budget upgrades.

Why Superannuation Earnings Can Move Tax Receipts

Superannuation funds generally pay tax on earnings in accumulation phase.

When investment markets perform more strongly than forecast, taxable investment income and realised gains can increase.

That can produce higher superannuation tax receipts than expected.

The same broad principle applies to investment income outside super, including taxable dividends, interest, rental income and realised capital gains.

When those income streams outperform assumptions used in Budget forecasts, tax collections can also exceed expectations.

A Hypothetical Superannuation Example

Consider a simplified hypothetical superannuation account with a $200,000 accumulation balance.

If the account generates taxable earnings of 5% during the year, that is $10,000 of earnings.

At a simplified 15% tax rate, the tax would be:

$10,000 × 15% = $1,500.

If taxable earnings instead reach 7%, the earnings amount becomes $14,000.

Tax at 15% would then be:

$14,000 × 15% = $2,100.

The difference is $600 from one account.

Across large numbers of superannuation accounts and investment portfolios, stronger-than-expected taxable earnings can materially change overall Commonwealth tax receipts.

This example is illustrative only because actual super fund tax outcomes can also be affected by capital gains treatment, franking credits, deductions and the timing of realised gains.

Investment-Driven Revenue Can Be Volatile

Revenue associated with investment income can change significantly from year to year.

Stronger equity markets can increase taxable capital gains and investment earnings.

A weaker market environment can reduce those receipts.

Interest income can also move with interest rates, while dividend receipts depend on corporate profits and payout policies.

This means an upside surprise in one financial year does not automatically establish the same revenue base for future years.

Forecasts therefore need to distinguish between structural improvements and temporary market-related gains.

The Budget Still Recorded a Deficit

The stronger-than-expected result did not produce a surplus.

The final underlying cash deficit remained $22.3 billion.

The previous year, 2024–25, recorded an underlying cash deficit of $10 billion, meaning the deficit widened in 2025–26 despite outperforming the May forecast.

The May Budget also forecast a deficit of $31.5 billion for 2026–27.

This means the fiscal position still depends on the interaction between receipts, spending, economic growth and financing costs over the coming years.

Lower Payments Also Helped

Revenue was not the only reason the final deficit improved.

Government payments were $1.4 billion lower than forecast for 2025–26.

Even relatively small changes in major spending programs can have a meaningful effect on the final budget result when aggregated across the Commonwealth.

Lower-than-expected payments therefore complemented the stronger tax receipts and helped narrow the deficit compared with the May estimate.

What the Outcome Says About the Tax Base

The Final Budget Outcome illustrates how Australia's tax base is influenced by more than wages and company profits.

Superannuation tax, investment income, capital gains and other asset-related income can all affect Commonwealth receipts.

That matters because the mix of revenue can influence how sustainable a tax upgrade is.

Wage and salary tax receipts tend to be linked to employment, wages and bracket settings.

Investment-related tax can be more sensitive to financial markets, asset prices and realised gains.

The 2025–26 outcome shows that those asset-related revenue streams can materially affect the budget when they differ from forecast assumptions.

Current Tax Settings Are Unchanged by the Outcome

The Final Budget Outcome reports what happened during 2025–26.

It does not itself change individual tax rates, superannuation tax rates or lodgment obligations.

Taxpayers should therefore distinguish between a stronger-than-forecast revenue result and an actual change in tax law.

Current tax obligations continue to depend on the legislation applying to each income year.

The Next Budget Test

The next major fiscal update will show whether stronger superannuation and investment receipts are expected to continue.

If Treasury judges the improvement to be persistent, some of the additional revenue could be incorporated into future forecasts.

If the increase is viewed as largely temporary or market-driven, future projections may remain more conservative.

That distinction will matter for the projected 2026–27 deficit and the medium-term budget outlook.

Why Market Conditions Matter

Financial market performance will remain an important factor.

Stronger asset prices can increase realised capital gains and superannuation investment income.

Higher interest rates can lift taxable interest income for savers, although they can also increase government borrowing costs.

Weaker markets can produce the opposite effect.

This means revenue and spending can move in different directions at the same time.

A better revenue outcome does not necessarily translate directly into an equally large improvement in the overall budget balance.

What to Watch Next

The next major update will be the Mid-Year Economic and Fiscal Outlook.

It should provide further information on whether the stronger superannuation and investment income collections are being incorporated into forward estimates or treated as a largely one-off improvement.

The 2026–27 Budget currently forecasts an underlying cash deficit of $31.5 billion for the year.

Investment markets, wages, economic growth, government spending and interest costs will all influence whether the final outcome differs from that forecast.