Asda's card machine system has crashed, leading to queues at the store's checkouts across the UK.
Asda has said it is still working to fix the issue.
The fault has affected stores in Liverpool, Birmingham, Essex, Manchester, Cornwall and Essex.
Customers took to social media to share pictures of lengthy queues and ask the company for more information:
Gordon Carr from Gateshead wrote on twitter: "Thanks very much asda I have lost my 'extra' hour today waiting at Boldon store as tills stopped working! 45 minutes with no explanation."
Jim Bentley tweeted: ".asda no backup, no redundancy system. We're just stood here like cattle waiting for your systems to start working again. On Sunday."
Graeme Barbour wrote: "Seems to be technical issue at £Basingstoke asda - no tills taking card payments, only cash. Customers requested to draw cash from ATM."
Asda's customer service team tweeted to say it was working to resolve the issue as soon as possible and said it was "sorry for any inconvenience caused".
An Asda spokesperson said: “We are in the process of resolving a technical issue with our card payment system in stores.
"We're continuing to process payments as quickly as we can but apologise to our customers for the inconvenience this has caused.”
