Monday has been dubbed Cyber Monday after it was revealed as the busiest day for online retailers so far this year.
According to card fraud prevention specialist Retail Decisions, the biggest online shopping hour was between 1 and 2pm when Brits spent £33m.
However, according to the web metrics firm Hitwise the number of visits to online retailers made on Sunday December 6 equalled those made the following day.
"Many industry observers consider 'Cyber Monday' to be the busiest day of the year for online retailers, but the Sunday before Cyber Monday is just as important in terms of internet visits," said Robin Goad, research director at Experian Hitwise.
"Many consumers spend time browsing and comparing products and prices on the Sunday, before making their actual purchases on Cyber Monday itself."