Customers at the Sainsbury’s store in Stanway endured long queues on Saturday morning, with contactless payments unavailable whilst many people had their credit or debit cards declined.
Some shoppers were forced to queue at a single cashpoint outside the store so they could pay for their items.
Others had to abandon their shopping altogether.
Customers who had to withdraw cash then had to have all their items re-scanned, causing further delays.
One member of staff at Sainsbury’s Stanway said the problems started as early as 6am on Saturday morning, with the retailer later announcing on X the problems had been caused by “an error with an overnight software update”.
As shoppers entered the store, they were told by members of staff the scan-and-shop service was unavailable and they would have to pay using chip and PIN transactions.
Customers were also warned Santander, Bank of Scotland, and Lloyds cards were likely to be declined.
It resulted in long queues at conveyor belts across the supermarket, although it is understood the problem is affecting Sainsbury’s stores across the UK.
One shopper remarked: “It is amazing how much we have liked being able to do things so simply.”
A statement from Sainsbury’s, posted on X at 8.35am, read: “We’re experiencing technical issues affecting some stores, our Groceries Online service and our ability to contact customers.
“Unfortunately, we will not be able to fulfil the vast majority of today’s Groceries Online deliveries.
“We are working hard to fix the issue and apologise to our customers for the inconvenience.”
A second statement at 12.07pm blamed the issues on a software error.
It read: “Due to an error with an overnight software update, we are experiencing issues with contactless payments and will not be able to deliver the vast majority of today’s groceries online orders.
“Our stores are open as usual, accepting chip and pin and cash payments.”