A Visa spokesman said: "Visa is now experiencing a service disruption".
This problem, a nationwide Visa outage had also affected the European Union but it seems to be more or less back in action and working to full affect today as Visa issued an apology to customers late last night.
United Kingdom bank NatWest said it was also looking into reports of card payments being declined.
Finance experts Payment Sense said at 6.30pm the problem is slowly being fixed and some cards have begun to work again.
This has left some customers unable to use their cards to make payments for goods and services in shops and at tills.
The issue was not associated with any unauthorised access or cyber-attack, the statement said.
Pareja espera a su hijo número 21
Así, la familia récord se agrandará a pesar de que los padres habían dicho cuando nació el último bebé que no tendrían más hijos . Cada día, la familia consume nueve litros de leche , cinco litros de juego y se comen tres cajas de cereal durante el desayuno .
Still, ATM transactions are not affected and so aren't Mastercard and American Express, so consumers have backup payment options.
"If you attempted a Visa transaction that did not complete as a result of this issue, you should not be charged".
Some customers have reported that funds appear to have been taken from their accounts, despite payments being declined in-store.
Paymentsense, which provides card machines, online payment gateways and virtual terminals to some 60,000 independent businesses in Ireland and Britain, advised users to try paying via contactless transactions.
Virgin Trains told one customer: "Unfortunately unless you have another form of payment then you wouldn't be able to get a drink".
An estimated £1 of every £3 spent in the United Kingdom is on a Visa card. "We fell well short of this goal today", he admitted.