Shoppers at Sainsbury’s and Asda were among those who complained that their card payments were blocked on Thursday morning, leaving some supermarkets only able to accept cash.
The supermarkets apologised to customers who said they could not pay for their shopping on Thursday morning due to the technical issues.
People took to X, formerly Twitter, to complain that they had taken their shopping baskets to the till but been told that they could not pay by card, or had seen “cash only” signs temporarily placed in stores.
Sainsbury’s told customers it had been made aware of a nationwide issue with card payments in the morning, but said the problem had now been fixed.
A spokeswoman said: “Contactless payment is back up and running after being briefly unavailable for a few minutes earlier this morning.
“This was due to an issue with our third-party payment provider.
“We’re accepting all payments as usual and we’re sorry for any inconvenience this may have caused.”
The issues appeared to stem from a provider which helps process card payments for some retailers.
Worldline said it had experienced a service disruption which meant some retailers may have faced problems processing transactions in store, between about 9am and 10am.
It later said the service had been fully restored but apologised for the temporary outages.
Asda also apologised to customers on X who said their local stores were only accepting cash payments in the morning.
Payments firm Visa confirmed that its systems were working normally on Thursday.
A spokesman for Visa said: “We are aware that a merchant payment provider reported issues this morning that impacted some cardholders.
“It has been reported that this issue is now resolved. Visa’s systems continue to operate normally.”
Mastercard also confirmed that its own network was running fine and said the morning’s issues “were not related to our systems” after investigating them.
The problems are the latest in a line of technical issues affecting banking firms and digital payments in recent months.
Last month, outages affecting the UK’s network meant that some people were unable to send and receive payments through online and mobile banking.