Australians are expected to treat themselves after a tough year by embarking on a record post-Christmas splurge in an unlikely spending trend.

The first restriction-free Boxing Day sales in three years kick off on Monday as rising living expenses weigh on household budgets.

But despite the cost-of-living pressures, shoppers are expected to splurge a record $23.5 billion and attract more digital traffic than Black Friday sales in November.

That’s an almost 8 per cent rise in spending compared to this time last year.

The Australian Retailers Association said after a rough year, many shoppers were rewarding themselves in a “freedom spending” trend.

“It’s been a tough year for many and this year we are seeing what we are calling ‘freedom’ spending, where people reward themselves after an intense and challenging period,” said ARA chief executive Paul Zahra.

Roy Morgan analysts anticipated NSW shoppers would spend the most, up an expected 9.5 per cent on 2021.

Food, household goods and clothing are expected to be the top three most popular categories.

• Related: The bargains Aussies want to bag on Boxing Day

The post-Christmas shopping period covers December 26 to January 15.

Mr Zahra said retailers were expecting a spending slow down in 2023, but the predicted results were encouraging.

“It’s clear to see Australians’ love affair with shopping continues,” he said.

“Shopping and dining out remain some of our most beloved pastimes through the holiday season.”

Shoppers are expected to crowd the Sydney CBD, as NSW outspends the nation. Photo: AAP

Mr Zahra said shoppers tended to wait for Boxing Day discounts to spend on themselves, whereas pre-Christmas spending was usually reserved for gifts.

But he acknowledged inflation and unseasonal weather was likely skewing the spend predictions upwards.

The Nation Retail Association predicted a $3 billion spend in Boxing Day sales alone across Australia.

Interim chief executive Lindsay Carroll said despite the growing popularity of Black Friday and Cyber Monday, Boxing Day still reigned supreme for Australian shoppers looking for a bargain.

Ms Carroll said while online shopping had grown in popularity, 50 per cent of shoppers still preferred to head to stores in person.

Aussie travellers looking for bargain airfares could also be in luck with budget airline Jetstar promising sales on more than 80,000 domestic and international fares in the next 48 hours.