Retailers reported a fine start to the post Christmas sales despite a disappointing pre-festive shopping period.
Shoppers were queuing from as early as 0700 GMT in Birmingham
Up to 40% of large stores opened their doors as bargain hunters braved the icy conditions.
The British Retail Consortium (BRC) has predicted shoppers will spend more than £5bn in the days after Christmas.
But many shoppers have already taken advantage of stores' decisions to cut prices before Christmas.
At Birmingham's £530m Bullring complex, consumers were queuing from early as 0700 GMT - four hours before the start of trading.
Within the first hour, more than 22,000 shoppers passed through the complex's doors, compared to 17,000 in the same period in 2003.
Around 150,000 are thought to have spent part of Boxing Day buying goods at the mall.
Many stores opened on 26 December for the first time last year and reported healthy sales.
Half of the 330 stores in the Bluewater Shopping Centre in Kent opened for six hours, compared with only a few in 2003.
Marketing manager Alan Jones said: "I wouldn't say it's been absolutely manic, but we estimate that about 100,000 people have been through the doors.
"I expect it to be far busier on Monday because Boxing Day has only been a six-hour trading day."
Major stores beginning their post-Christmas sales included Marks & Spencer, Argos and Debenhams.
Officials at the Trafford Centre in Manchester said that around 100,000 people passed through its doors by the end of Boxing Day.
Spokeswoman Hannah Foster said: "We have obviously been open only Sunday trading hours of noon-6pm, so in terms of visitors per hour, the number of people is probably one of the highest that we have had in the year."
Only one of the centre's 230 shops was not open and queues started to form from 0900 GMT.
But across the West Midlands in Dudley, the Merry Hill Centre reported that Boxing Day trade, was not as buoyant as in previous years.
Centre bosses blamed heavy discounting for "sluggish" sales growth.