A study of 2,000 adults found the average online shopper will put clothes and gadgets worth £4,283 a year into their baskets, but don’t get around to hitting ‘confirm’.
This fantasy check-out total includes £480 worth of clothing, £571 of home accessories and £500 of health and beauty items.
A further £554 is abandoned by individuals when food shopping each year and £586 when browsing for technology.
Causes of abandoned baskets include being put off by the cost of postage and packaging (26 per cent), wanting to research and compare prices on other websites (20 per cent) and finding there were too many steps in the check-out process (11 per cent).
The least loyal shoppers were found to be those browsing for clothes (22 per cent), while shoes (10 per cent) and books (10 per cent) also regularly end up on the shopping scrap heap.
It also emerged one in five adults have noticed an increase in suspicious looking websites.
And more than one in 20 abandoned a purchase after being asked to approve a transaction in their banking app which seemed dubious.
Nationwide Building Society carried out the research to highlight the new Strong Customer Authentication check – where customers need to verify it’s them making the transaction by inputting a one-time passcode or by authenticating the payment within their banking app.
Spokesman Matt Cox said: “The results show we’re a nation of online shopping fans, yet often get carried away with ‘fantasy’ baskets and end up abandoning lots of items.
“The numbers put into perspective just how much is left behind by indecisive shoppers.
“But brands do have a clever way of drawing people back in to complete a purchase, whether with an offer, a reminder email or targeting them with social media adverts.
“While the nation loves online shopping, so do the fraudsters, which is why this new protection has been brought in.
“To date, the SCA check means Nationwide is seeing 2,000 fewer cases of online card fraud a month, which will be replicated across banks and building societies and whilst the battle against fraudsters is never over, SCA represents a big step forward.”
The study also found online shoppers spend an average of three-and-a-half hours browsing and purchasing online a month, and typically receive four deliveries each.
Although 21 per cent obtain 10 or more parcels in that time.
Almost three quarters (73 per cent) have revisited an abandoned basket to make a purchase, convinced by an incentive to buy (18 per cent), an email reminder (13 per cent) and loyalty points (10 per cent).
But while it took 26 per cent several hours to revisit, 14 per cent admitted they only waited a few minutes.
When online shopping, four in 10 have been worried about their card details being compromised and 59 per cent have had concerns around them being stolen or used by someone else online.
It also found seven in 10 have been asked to enter a one-time passcode to verify the purchase in their banking app, but this meant 21 per cent were unable to make their purchase.
This was down to not having their phone on them to use the app, no Wi-Fi signal and even not owning a mobile.
While 22 per cent of those polled via OnePoll did successfully make their purchase, it took longer than usual.
Matt added: “By now most people who shop online will have come across a ‘Strong Customer Authentication’ check when they go to pay for their online shopping.
“This check will add just a few seconds to the checkout process, but it is having a big impact protecting consumers from online fraud.
“Security and convenience is important which is why most people are happy for the check-out process to take a little longer and say they feel safer knowing this check is in place.”
The cost of items left abandoned in shopping baskets per adult each year
Clothing - £480
Fashion accessories - £523
Health & beauty – £500
Home accessories - £571
Entertainment - £506
Food & Drink – £554
Gadgets & technology - £586
Homewares & DIY - £562