The issue appears to be due to this latter system, with Visa's network also forming the backbone for many financial institutions. "We will keep you updated".
A Visa spokesperson confirmed the outage today (June 1) and said the company is investigating the cause while trying to resolve it "as quickly as possible".
Scores of people posted on our Facebook page to say they had been rejected at various shops using different bank cards.
Peter Hahn, professor of banking at the London Institute of Banking and Finance, said that consumers in the modern world should be ready for this eventuality.
Customers around Europe vented their frustrations on social media, with some unable to pay bills or order taxis overseas.
Users of many United Kingdom banks have received alerts or messages informing them of a "disruption of service" which means they can not spend or receive money.
On Twitter HSBC told customers that there had issues with Visa's payments processing but said: "From what we understand there are still intermittent issues but services are slowly recovering".
"I knew I had to get out of that job because I'm sitting in front of a computer for too many hours of the day".