Christmas spending is set to fall for the first time since 2012, owing to Brexit uncertainty and a drop in real wages, according to research compiled by IHS for Visa.
High street shops are expected to suffer a 2.1 percent drop in spending, making it the third straight year that shopping at bricks-and-mortar stores.
That forecast suggests consumers will seek bargains, but according to Which? shoppers may find that Black Friday does not deliver the big discounts that many might otherwise assume.
Which? tracked the Black Friday prices of 35 of the most popular technology, home and personal care products sold by Currys PC World, Argos and Amazon and it found that 60 percent of the deals could have been found at other times during the year, or for a cheaper price.
UK shoppers are expected to spend some £2.6bn - an eight percent increase on the £2.4bn spent last year - or £1.8m per minute snapping up deals online and in stores this Friday, according to predictions from VoucherCodes and the Centre for Retail Research.
The consumer group urged shoppers to research reviews and regular prices before Black Friday so they know if they are getting a good deal, and to shop at retailers with price promises to increase the chance of a part-refund if an item drops in value in the weeks following purchase.
Alex Neill, Which? managing director of home products and services, said: “It’s easy to get swept along by the hype and excitement on the day, so we recommend doing some preparation and research to help make sure you really are getting a good deal.”