Visa has apologised after a system failure prevented card payments across the UK and Europe.

The company said on Friday night that it "fell well short" of its goal to ensure cards work reliably at all times, but assured customers that Visa is now operating at "close to normal levels".

Visa users complained about the issue on social media on Friday evening, which was the result of a hardware failure.

A Visa spokesman said: "Earlier today, Visa had a system failure that impacted customers across Europe.

"Our goal is to ensure all Visa cards work reliably 24 hours a day, 365 days a year.

"We fell well short of this goal today and we apologise to all of our partners and, most especially, to Visa cardholders.

"Visa cardholders can now use their Visa cards as we are currently operating at close to normal levels.

"The issue was the result of a hardware failure. We have no reason to believe this was associated with any unauthorised access or malicious event."

The apology came after customers across the UK and Europe were unable to pay for some of their purchases with Visa cards after the network was thrown into chaos.

Thousands of people had their cards declined at supermarkets, major retailers and on public transport.

The card payments network, which can process up to 65,000 payments a second, said "service disruption" in Europe had stopped transactions from being processed.

Shoppers reported being stuck in queues in supermarkets and petrol stations as Visa transactions could not be processed.

Some retailers resorted to putting up notices to warn customers that they are unable to take card payments.

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Banks told customers they could still withdraw cash from ATMs.

Visa has not yet stated whether retailers will be compensated for lost earnings.

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Payment processing through Visa's systems accounts for £1 in £3 of all UK spending, the company said.

Deborah Elder, from Glasgow, was unable to pay her restaurant bill while she was waiting at Frankfurt airport to fly back to Toulouse.

She said: "I was so embarrassed. I gave the waiter the 14 euros I had left.

"I'm worried I won't be able to get home when I land in Toulouse as I have no cash for a taxi."

Retailers including Marks & Spencer and Sainsbury's confirmed they had been affected.

The National Lottery was also forced to respond to complaints after angry customers were unable to access their funds or add money online, while staff in some John Lewis outlets said Visa payments had been going down sporadically. 

There were long queues reported in Marks and Spencer and Paperchase branches.

Which? has warned that the widespread network failure could attract scammers, and advised people to be “extra wary” of calls or emails related to the outage.

They advised people to keep evidence of extra expenses they've incurred in order to claim them back later.

Alex Neill, Which? managing director of home products and services, said: "Clearly this issue will be a huge inconvenience to customers and it must be resolved urgently. Visa and the banks need to ensure no-one is left out of pocket due to this outage."

A Bank of England spokesman said they were aware of the problems affecting Visa across Europe and were working with the firm to resolve the situation.

UK Finance, the trade association which represents leading firms in the payments industry, said: "Visa is currently experiencing a service disruption which is preventing some Visa transactions in Europe from being processed.

"It is investigating the cause and acting as quickly as possible to resolve the situation. Visa is working with banks, building societies, merchant acquirers and card providers to return to a normal service and will provide regular updates."

National Crime Agency spokesman said that although they were taking an active interest in the unfolding problems and would discuss any relevant issues with partners, they had not been contacted by Visa.

Action Fraud, which would usually be the first port of call if suspicious activity was detected, also said it was not something of which they were aware.