Treasurer Jim Chalmers has left the door open for further cost-of-living relief for struggling Australians, as he confirmed a second straight surplus.

Chalmers and Finance Minister Katy Gallagher confirmed the $15.8 billion surplus for the 2023-24 financial year on Monday – a $6.4 billion improvement on forecasts in the May budget.

The final budget outcome showed the budget being $6.5 billion higher than forecasts put forward in May. It’s the first time a government has handed down a consecutive surpluses since 2007-08.

Chalmers said the result was largely due to lower government spending.

“This surplus is bigger at the end of the financial year than we anticipated in May, not because taxes are higher, but because spending is lower,” he said.

“Spending in the last financial year was much lower than anticipated at budget and revenue was lower as well. Spending was down by around twice as much as revenue was down.”

He said the surpluses were about fighting inflation and “providing room for cost-of-living relief”, as well as paying down debt.

“One of the reasons we are proud of the consecutive surpluses that we’ve delivered for the first time in almost two decades is we haven’t done that or cost-of-living relief. We’ve done that and cost-of-living relief,” Chalmers said.

“We understand the pressures that people are under. We’ve deliberately ensured that we have found room for that cost-of-living relief so that we can help people doing it tough.”

He listed the Albanese government’s rebooted stage-three tax cuts, energy bill relief for households, cheaper early childhood education and increases in Commonwealth rent assistance as cost-of-living measures already delivered.

Gallagher said the back-to-back surpluses were the “culmination of a lot of work over a couple of years”.

“It’s so that we can make room for the important things that people really value in the community – more housing, better Medicare services, cheaper medicines, and cost-of-living help when they’re doing it tough,” she said.

“We’ve only been able to find the room to do that because of the approach that we’ve taken in the last budget [and] three budgets since we came to office.”

The government returned 87 per cent of revenue upgrades to the budget last financial year since the pre-election economic and fiscal outlook.

Payments as a share of gross domestic product in 2023-24 were 25.2 per cent, lower than the 27.1 per cent previously forecast.

The surplus is expected to make up 0.6 per cent of the nation’s total economic output.

Chalmers said while commodity prices had been higher, they were not the only reason for the surplus.

“The improvement from our expectations of the surplus in May to the final budget outcome that we’re reporting today is not about more revenue, it’s not about higher commodity prices, it’s not about more taxes – it’s about the less spending,” he said.

“We always take a deliberately conservative approach to commodity prices, and that’s been warranted.”

While consecutive surpluses have been locked in, the government has forecast a deficit of $28.3 billion for the 2024-25 financial year. Although that had been reduced from an initial forecast of $47 billion, Chalmers said it was “difficult to see” a third surplus.

“I’m not going to speculate about what that update might say when we release it closer to Christmas,” he said.

“Clearly, a $28 billion deficit is hard to get rid of in one whack, but we will continue to make the right decisions for the right reasons and manage the budget and the economy in the most responsible way.”

Opposition finance spokeswoman Jane Hume said higher deficits were on the way and the extent of the surplus was exaggerated.

“It looks like those surpluses that Jim Chalmers has delivered have been delivered not by his hard work but by [taxpayers’] hard work,” she told Sky News.

“Jim Chalmers inherited a strong economy with low levels of unemployment, and in fact, we’ve seen a deteriorating position since then.”

Meanwhile, Tasmanian senator Jacqui Lambie said the improved budget bottom line did not mean much for people dealing with the increased cost of living.

“People are doing it hard out there. Nobody’s talking about a surplus,” she told Nine’s Today program.

“If they were, and they truly understood that, well how about you put some of that surplus out to us so we can put bread and milk on the table for our kids and do that without raising inflation?”

-with AAP