Credit card giant Visa's authorisation system has been suffering from a system failure since the early hours of this morning, leaving some merchants unable to authorise transactions.
One Reg reader alerted us to the issue which could prevent thousands of online Visa card transactions from being processed today.
An email from one payment service provider reads: "Our systems indicate that this problem occurred between approximately 5:10 and 8:24 BST. During this time period, authorisation requests on some Visa branded cards did not receive any bank response."
A spokesman at the credit card firm confirmed to The Reg that Visa had experienced "some technical problems" since early this morning.
He said the extent of the problem was yet to be determined and that "immediate backup measures had been put in place".
However, he conceded that "undeniably, some transactions will not have processed".
The spokesman was unable to confirm how many Visa payments had been affected by the system failure. He said "at this point I don't have any definitive numbers" but insisted that in the UK the impact appeared to be minimal due to the backup procedure that had been put in place.
Elsewhere in Europe the picture looked slightly different, with Hungary and the Czech Republic having been more heavily hit by the system failure.
Visa is currently carrying out diagnostics and hopes the system will be up and running soon, but was unable to confirm when customers can expect the service to be operating as normal. ®