Government income in 2025/26 was up by $4.6 billion since the May budget forecast, Treasurer Jim Chalmers said when announcing the final outcome for the financial year on Monday.
That was due to higher-than-expected tax returns from superannuation funds and investors.
"This is not about wage and salary earners," Dr Chalmers said.
"It's not about commodity prices," he said, noting mining profits came in lower than anticipated.
Payments were also below expected levels, down by $1.4 billion on budget forecasts.
That was, in part, because of decreased spending in the aged and child care sectors.
But defence and health expenses were both more than $1 billion above projections.
The overall result was an improvement to the underlying deficit, which was previously projected to be $28.3 billion. Instead, the deficit came in $6 billion lower.
It's still a good deal worse than the previous year's final budget outcome, which put the deficit at just under $10 billion for 2024/25.
"Despite this very welcome improvement in the budget, we know that pressures are intensifying rather than easing," Dr Chalmers said.
Inflation is still stubbornly above the Reserve Bank's two to three per cent target band, with the Middle East oil shock set to keep price pressures elevated.
The bank's board is widely expected to increase the cash rate to 4.6 per cent - the highest level in 15 years - when it wraps up its two-day meeting on Tuesday.
Dr Chalmers would not be drawn on whether the government's fiscal settings would directly impact the expected rate rise.
"We acknowledge the independent Reserve Bank has its own job to do," he said.
"Our job is to continue to manage the budget in a responsible way and take this productivity challenge seriously."
He instead pointed to global economic strains putting pressure on interest rates, adding his government was taking productivity gains more seriously than any other in decades.
The US, Europe and Japan have all hiked interest rates due to rising fuel costs since the RBA met in August.
Hawkish comments from governor Michele Bullock and other top RBA officials in recent weeks have emphasised the bank is losing patience with inflation and is likely to follow suit.
Opposition MPs have sought to pin the inflation spike on government spending, despite growth in public demand moderating in recent years.
"The rest of the world is not experiencing the inflation that we are experiencing here at home," Liberal MP Zoe McKenzie told News24.
"The average Australian household with a mortgage is already having to find more than $30,000 a year in after-tax dollars just to meet the interest payments on their mortgage," she said.
Tobacco brought in $200 million less than projected, at $3.9 billion, the final outlook showed.
Petrol was down $100 million, bringing in $6.3 billion worth of receipts.
Brent oil futures have risen to $US106 a barrel after peace talks between the US and Iran hit another snag.
Each $US1 dollar increase in the Brent oil price roughly translates to a 1c increase in fuel prices at the bowser.
Those higher servo costs will likely nudge headline inflation from 3.5 to four per cent by the time the Australian Bureau of Statistics reports on Wednesday.
