Visa services have returned to normal after a hardware failure left customers across Europe unable to make some payments.
The company released a statement on Saturday morning, saying its systems were now working at "full capacity".
Visa issued an apology and said the outage was not down to "unauthorised access or a cyber attack".
Payments processed through Visa's systems account for £1 in £3 of all UK spending.
Shoppers were stuck in queues, diners were left embarrassed and one MP even drove away from a petrol station without paying as the issue affected Visa Europe's systems on Friday.
Elle Gibbs-Murray, from Bridgend, said she was stuck in traffic on the Severn Bridge for 45 minutes as drivers were unable to pay the toll by card.
And Jay Curtis, from Swansea, had two cards declined in B&Q when he tried to pay for £240 of goods.
"My card just wouldn't go through," the 32-year-old told the BBC.
"I didn't have cash on me so I had to drive all the way home."
On Friday, Visa said the system was "close to normal" five hours after publicly acknowledging the problem.
The company's chief executive, Al Kelly, apologised for the trouble caused by the hardware failure.
"Our goal is to ensure all Visa payments work reliably 24 hours a day, 365 days a year," he said.
"We fell well short of this goal today and we apologise to all of our partners and Visa account holders for any inconvenience this may have caused."