Morrisons has apologised after customers have been unable to get discounts on their shopping ahead of Christmas after a problem with the More loyalty card.
Some customers have also complained that their online orders have been cancelled.
The supermarket says loyalty card and click and collect orders are mostly affected.
“If More Card prices are not registering, we will apply a 10% discount to the customer’s entire shop,” a Morrisons spokesperson said.
They added that some home deliveries may be arriving late today, and that click and collect customers should wait for an email before going to the stores.
One customer told the BBC she has missed out on her online order, which included a turkey and trifle that was meant to arrive this afternoon.
“I booked it ages ago, when the delivery slots first came out for Christmas,” says Moira Redhead, from Northumberland.
She is unable to leave the house due to illness, and is waiting for a medication delivery today.
“I’m really stressed, I don’t know what I’m going to do,” she says.
“[Morrisons] said they couldn’t do anything… they also said their systems were down,” she adds, saying that Morrisons offered a £10 goodwill voucher.
Another customer says he missed out on about £20 of discounts.
“I added everything up as I went around the shop and it came to £70, which with all my card discounts and vouchers should have cost me nothing at the checkout,” Steve Weatherby, from Huddersfield, told BBC News.
“But it came up as £90. None of the discounts and offers around the store, like 50p off, had been applied.
“So I had to pay it as I was shopping for Christmas lunch and things we needed.”
He added: “The staff were getting upset as they weren’t aware of what was happening, and it’s not their fault.”
Social media users say their discounts are not working at the till, with one person posting a photo of an error message at the self-checkout, which reads: “We are really sorry some promotions and discounts are not working at this time.”
The Morrisons website was also down for a period in the morning, with error messages on some pages suggesting invalid or late responses from servers.
It now appears to be back up and running.
‘Stuff of nightmares’
Morrisons had been advertising large discounts ahead of Christmas, including some vegetables for 10p.
“There’s never a good time for a tech glitch, but for it to happen on what is expected to be the busiest day of the year is the stuff of nightmares,” says retail analyst Natalie Berg.
“This will further erode shopper trust and impact profitability.
“Supermarket margins are razor-thin to begin with and this Christmas has been especially promotional,” adds Ms Berg.
“This problem just shows how reliant supermarkets are on their systems to ensure that the millions of shoppers who shop with them have seamless experience,” says Katherine Shuttleworth, retail analyst at Savvy Marketing.
“A systems glitch like this couldn’t come on a worse day,” she adds.
Today is predicted to be the busiest shopping day for supermarkets this year, according to retail analysts Kantar.
Sales at supermarkets are expected to reach over £13bn for the first December ever.
Morrisons is the fifth-largest market supermarket in the UK, according to Kantar, with 8.6% of the grocery market in the 12 weeks leading up to 1 December 2024.
“Retailers are putting more and more deals through their loyalty cards and if shoppers can’t access them, they will feel cheated,” said Ronan Hegarty, news editor of trade publication The Grocer.
“That it has happened so close to Christmas will leave a bad taste in customers mouths and have them thinking about where to shop next.”