A grocery chain says it's facing a rise in 'fraudulent coupons' as social media users brag of huge discounts on their shopping

• Some shoppers at UK grocery-store chain Sainsbury's say they've got huge discounts using its app.
• They appear to have repeatedly scanned a coupon at its self-service checkouts, taking large discounts off their shop.

A UK grocery chain says it has been dealing with an increase in "fraudulent coupons" after social media users bragged of getting huge discounts on their shopping by repeatedly scanning the same coupon.

Videos posted on social media, some of which have gained millions of views, seem to show some Sainsbury's customers getting massive reductions on their shops when they use its self-service checkouts by scanning screenshots of a promotional coupon on the retailer's app multiple times. The coupons don't appear to be tied to particular items.

The Sun newspaper quoted one shopper who it said had used the coupons and purchased around £80 ($103) worth of items for less than £2 ($2.58).

In some videos, shoppers said that they'd been getting their groceries as well as items like air fryers, blenders, and vacuums for rock-bottom prices.

Many of the videos asked viewers to send them messages or join Discord groups to get access to the coupons.

Business Insider was unable to independently verify the claims made in the videos.

The Grocer, a British publication focusing on the grocery store trade, said that a step-by-step guide on using the coupons had been shared via a voice note on messaging platform WhatsApp.

Retail Gazette reported that the coupon appeared in Sainsbury's app on Monday.

"We have seen an increase in fraudulent coupons in our stores and we have processes in place to detect and block them," a Sainsbury's spokesperson told Business Insider. "We also have in-store detectives monitoring for fraudulent attempts and we are working closely with the police on this issue."

Sainsbury's would continue to accept "genuine" coupons, the spokesperson said.

At a Sainsbury's store in London, signs on the door and by the self-service checkouts repeated these remarks, adding that the checkout process might take "slightly longer" than usual.