Treasury will open the Government's books today revealing the state of its finances after one of the most difficult fiscal years in recent history.

The publication of the end-of-year accounts also kicks off the budget process for 2023, which Finance Minister Grant Robertson has signalled as the beginning of a more restrained and "targeted" era of Government spending.

The Government's financial year begins in July and ends at the end of June - this year's accounts, beginning in July 2021 and ending this June capture the Delta and Omicron Covid outbreaks, along with their costs.

Prime Minister Jacinda Ardern foreshadowed the accounts might not be pretty for that reason. Speaking on Monday, Ardern said the accounts covered "the toughest period in our Covid response, including the responses to both Delta and Omicron".

"Without revealing the details, despite those challenges, we know our current position is strong. Our economy is now 5 per cent larger than before Covid.

"Unemployment is considerably lower than it was at the comparable period after the global financial crisis, and we've managed to achieve this with a similar debt level to what National took on as a percentage of GDP during the GFC."

The accounts also capture the winding-up of the Covid-19 response and recovery fund.

Forecasts released at the Budget in May showed Treasury reckoned the Government would face a $19 billion operating balance before gains and losses (Obegal) deficit this year, up from $4.7b the year prior.

Core Crown tax revenue would be $103.8b with expenses at $128.4b.

Net debt would be $61.2b or 16.9 per cent of GDP.

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Infometrics economist Brad Olsen said the expectation was for the Government's accounts to "track broadly in line with, and likely better than, expectations laid out in Budget 2022".

"Although the economic disruption from the Delta lockdown and the Omicron hit at the start of 2022 was intense, economic indicators suggest solid resilience in the face of everything," Olsen said.

"Analysis of business operating profits for most private sector parts of the economy show just a 0.7 per cent decline over the 12 months to June 2022 compared to a year earlier, all due to the Delta lockdown – June quarter operating profits rose 3.3 per cent pa, indicating solid activity," he said.

A deficit of $19b would be one of New Zealand's largest in nominal terms (2020 - the height of the pandemic, posted a $23b deficit). In the context of recent economic history, it would be broadly in line with other crises.

The deficit is expected to be 5.2 per cent of GDP. In 2011, in the aftermath of the financial crisis and Christchurch Earthquakes, the Government posted an Obegal deficit of 8.9 per cent of GDP.

The release of the Crown accounts marks the beginning of another budget cycle. It is the day when the finance minister announces when he will deliver the Budget Policy Statement - usually in December - which sets out how much new money they plan to spend in next year's Budget.

Robertson has already signalled next year's Budget will pivot from the Covid era of relatively large spending and stimulus.

Last month Robertson said the next steps of the Government's economic plan would involve investments "obviously not at the same scale as during Covid".

"With the emergency Covid response behind us now, we will enter a period of more targeted spending," he said.

He said a "tighter period will require some tough choices".

"At a broad level, my focus will continue to be on making sure New Zealand maintains responsible debt levels, and ensuring our path back to surplus," he said, adding this would not mean "austerity cuts to spending".

The Government is expected to return to surplus in 2025, and next year's Budget will have an operating allowance - the term for the amount of new discretionary spending - of $4.5b, down from $5.9b in this year's budget.

National's Nicola Willis argued that despite Robertson's ambition to return to more restrained spending, the damage was already done.

"If the accounts track to forecast then they will once again show record levels of Government spending. Labour is spending a billion dollars a week more than when they came to office.

"There has never been a Government that has spent so much taxpayers' money with so few results to show for it," she said.

Olsen reckoned the accounts would show increased spending and increased revenue reflecting the impacts of inflation and Covid-19.

"Sustained government spending, in response to the two Covid-19 waves in the last fiscal year, but also to address rising inflation and move forward parts of the Government's reform programmes, means that government expenses are also likely to be at or above forecast, although to a lesser degree than revenue," he said.

"The rise in revenue is partially going to be driven by rising nominal spending and earning, even as real underlying activity is weaker. Higher inflation is raising prices for goods and services, with higher GST earned on those higher prices. Higher wages, partially in response to high inflation, will also see more revenue collected from government," he said.

The accounts will be published at 1pm today. They are not the only big economic story of the day. The Reserve Bank will update the Official Cash Rate at 2pm, with another hike expected.