A delivery truck was leaving the Slough-based company's distribution centres every 8.5 minutes on December 4, its busiest day. Amazon says it dispatched more than 600,000 units - up 25% on last year and a company record.
Amazon, whose carriers include Royal Mail and DHL Express, says that 99.6% of products were delivered on time. Brian McBride, managing director, says that internet retailing had taken "another huge step forward this Christmas".