Shoppers are expected to splurge almost $24 billion in the Boxing Day sales.
The Australian Retailers Association says this will be around $400 million more than last year for the sales period between December 26 and January 15.
It's still the biggest shopping event of the year, despite the growth in popularity in recent years of the Black Friday and Cyber Monday events held in November.
The expected rise in spending equates to a 1.6 per cent jump, compared to 2022.
The association describes it as modest but still encouraging, considering cost-of-living pressures.
Roy Morgan research conducted for the association shows spending on food is forecast to reach $9.6 billion, up 2.8 per cent from last year.
Department stores will likely experience the biggest growth with spending up 4.8 per cent, followed by clothing at 3.4 per cent.
A state-by-state breakdown showed South Australians are expected to spend 2.7 per cent more than in 2022, above the national average of 1.6 per cent.
Association CEO Paul Zahra says Boxing Day is the "Grand Final" of shopping in Australia.
"Black Friday and Cyber Monday weekend demonstrated that shoppers will still spend if they feel that they're getting a great deal - and the sentiment towards the Boxing Day sales will be similar," he said.
In the lead-up to Christmas, shoppers are focused on buying gifts for family and loved ones, but from Boxing Day attention turns to themselves and their household, Mr Zahra added.
Sales in the pre-Christmas period from November to Christmas Eve were expected to rise one per cent to $67.4b, the Roy Morgan data showed, with $27b of that spent on food.
However, Black Friday and Cyber Monday sales are still fresh in shoppers' minds and people could be starting to get fatigued, according to Finder shopping expert Chris Jager.
"Shoppers have been bombarded with texts and emails for months on end leading up to all the major sale events," he said.
"Aussies are spending more than they had initially set out to do, due to fear of missing out.
"It's important to remember that just because there's a sale on doesn't mean you have to spend."
A Finder survey of more than 1000 people found one in three plan to shop the Boxing Day sales, spending about $356 each for a total of about $2.3b across the country.
E-commerce logistics platform Shippit expects sales to drop after Christmas because Australians spent big on Black Friday.
It predicts there will be about $150 million worth of transactions through its platform, less than half of what occurred over the last major sales event.
Consumer advocacy group CHOICE is encouraging anyone concerned about the quality of their Boxing Day purchases to be aware of their rights.
Campaigns and communications director Rosie Thomas recommended people contact retailers as soon as possible and said anyone who loses a receipt doesn't need to panic.
"Proof of purchase can include a credit or debit card statement, a lay-by agreement, and even a serial or production number linked with the purchase on the supplier's or manufacturer's database," Ms Thomas said.
