Christmas is still well over three months away but shoppers have reported their bemusement at supermarket shelves already stocked with mince pies and tubs of chocolates.
Tesco shoppers have found themselves confronted with banks of Quality Street and Heroes as they enter the supermarkets, while confused Asda, Sainsbury's and Morrisons customers have tweeted pictures of shelves packed with mince pies - despite the festive staple generally needing to be eaten fresh within a few days.
Retailers say the stocking of Christmas supplies in September - well before Halloween on October 31 - is simply down to demand from customers.
A Sainsbury's spokesman said: "We start to stock some festive products in advance of the main Christmas period as some customers like to be more organised and help spread the cost."
Some 8.6 million Britons have already started their festive shopping, a survey by American Express found.
Almost half (49%) of people start shopping early to pick up presents in the sales, while year-on-year data shows more Britons are getting a head start on shopping - since 2016 an extra 1.1 million people have started shopping with 100 days to go, the study shows.
Stephen Steinhardt, from American Express, said: "With so many people starting their shopping early the Christmas countdown is now well and truly under way.
"If you're not an early-bird shopper, it's a good idea to get started before it's time to dig out the tinsel and decorate your Christmas tree. This will avoid last-minute panic buying and help you spread the costs."
Selfridges, which opened its Christmas shop 145 days before December 25, said the ongoing commercial success of their summer launch translated into year-on-year record sales, driven by both domestic early Christmas shoppers and souvenir-hunting tourists.
Selfridges Christmas and home buyer Eleanor Gregory said: "Our summer Christmas shop launch simply addresses the growing demand for convenience Christmas shopping outside the traditional Christmas season from many of our customers.
"They include a large number of domestic customers who love to Christmas shop very early in the year to get it wrapped and taken off their to-do list."
Opinium surveyed 2,003 adults online for American Express between August 10-13.