Shoppers are predicted to spend £236 each on average in the Boxing Day sales this year, with the majority of purchases made online.
A total of £4.6 billion will be spent, a study by Barclays Consumer Spend researchers found.
Nearly half of respondents said the cost-of-living crisis will affect their post-Christmas shopping but the forecast average spend is still £50 more per person than it was before the pandemic, with some of that figure due to inflation, Barclays said.
Amid the financial pressures, many people are planning to buy practical, perishable and essential items such as food and kitchenware.
A total of 65% of shoppers are expecting to spend the majority of their sales budget online. Last year, Barclays found 63.9% of Boxing Day retail purchases were made online.
However, a quarter of respondents aim to spend mostly in-store – an 11% rise compared with last year.
This comes after major retailers including Next, Marks & Spencer and John Lewis announced they will not open their bricks and mortar stores on Boxing Day.
Karen Johnson, head of retail at Barclays, said: “Despite the ongoing cost-of-living pressures, it is encouraging to hear that consumers will be actively participating in the post-Christmas sales.
“This year, we’re likely to see a shift towards practicality and sustainability, with more shoppers looking to bag bargains on kitchen appliances and second-hand goods.
“Boxing Day continues to be a crucial time for the retail sector, and the renewed interest in in-store shopping, alongside the enduring resilience of online platforms, demonstrates a more balanced and adaptive approach from consumers, which we hope will continue into the new year.”
Consumers choose in-store shopping largely because they enjoy the social aspect and touching items before they buy, Barclays said, adding that high streets and shopping centres are the most popular destinations.
The researchers found a 7% rise in people planning to buy kitchen items such as kettles, air fryers and blenders this year, with groceries increasing by 5%.
“This marks a shift towards more functional finds, as Brits seek to use the sales to save on practical big-ticket items, which ordinarily fall outside their budgets,” Barclays said.
“Taking this a step further, a quarter (24%) say they will only be buying what they consider essential items in the post-Christmas sales.
“Similarly, the top motivations for post-Christmas sales shopping include replacing products that have run out (35%) or lost or broken items (31%).”
A third of respondents are expecting to shop on reseller websites as people post their unwanted gifts.
