Eight million online bargain hunters are expected to spend a record £636m on Christmas Day, up 25% on last year.
Shoppers will start logging on at 12.16pm to browse the Sales but will break for lunch and the Queen’s Speech, according to research from IMRG and Experian.
Up to 90% of Christmas Day shoppers will be using a tablet or smartphone.
Experian spokesman Giles Longhurst said: “The ease of shopping online with these devices means people can just slip away from families to hunt for bargains.”
Amazon has been heavily advertising its Christmas Day Sale on TV this week. It will offer discounts of 35% on 1,600 items from 4pm, and is predicting sales will peak at 9.02pm, according to The Mirror.
Deals include Clogau 9ct gold earrings down from £500 to £199.
Littlewoods’ deals will include £80 off Beats by Dr Dre headphones, which will retail at £139.
Ten million last-minute shoppers will hit the shops today, and are forecast to spend £870m, according to research by VoucherCodes.co.uk.