"Tesco said that all types of payments, including credit and debit cards and cash via normal tills, had been affected. However, self-service systems in affected stores and in Tesco garages had not been affected," reported ZDNet. "An investigation into the cause of the outage will be launched shortly, the spokesperson said, noting that the problem was probably caused by software updates that had been sent out on Sunday night. The issues were unlikely to have been caused by a hacking attack, the spokesperson added."
The 4,308-store Tesco grocery chain, one of Europe's largest retailers and the largest in the U.K., suffered some sort of a systems glitch during "an IT update overnight" that shut down POS systems for about 100 stores on Monday (May 11), but spared all self-checkout stations, Tesco officials said. Given that a retail self-checkout system typically runs its own application separate from the POS app, said IHL President Greg Buzek, this suggests the problem was internal to the POS software, not the payment application or database.