The total spend is predicted to rise by 12% from 2016, according to VoucherCodes and the Centre for Retail Research.
Barclaycard, meanwhile, says one in three Britons (34%) will go to the festive sales - up from 23% last year.
A poll for the company found that months of "feeling the squeeze" this year is resulting in many consumers looking forward to the sales to ease their budgets.
It would represent somewhat of a recovery for the tradition post-Christmas price drop, which was affected last year by an extended period of sales for Black Friday.