Hallowe'en is now the third largest retail season after Christmas and Easter, with shoppers likely to pay out between £315m and £325m on costumes, confectionery and even pumpkins, according to Planet Retail.
The trick-or-treat influence of the US and the availability of a wider variety of spooky-themed products have contributed to a steady rise in Hallowe'en spending over the past decade.
The UK paid just £12m for Hallowe'en goodies in 2001. This year's estimate is significantly up on the 2012 figure of £285m.
Sophie Carroll, associate analyst at Planet Retail, said: "This rise reflects a more favourable economic climate, as well as an increased Hallowe'en focus on the part of retailers, with competitive in-store prices on associated products and accessories.
"Though now established as a significant UK retail season in its own right, the British passion for Hallowe'en remains fuelled by US cultural influences, with the popularity of TV shows such as The Walking Dead and the Twilight movie franchise inspiring interest in the festival from across all ages."
In the run up to October 31 supermarkets have been filling their shelves with Hallowe'en-themed goods.