The Financial Conduct Authority is launching an investigation into Britain's banks' IT systems after a raft of glitches hit millions of customers across the industry.
Clive Adamson, FCA director of supervision, said: "To access and manage our money we depend on the banks' IT systems to be reliable. But IT outages continue, interrupting key banking services."
In January, Lloyds Banking Group became the latest lender to report a mass debit card and ATM outage as the result of a banking glitch.
For three hours on 26 January, the group confirmed around half of its 7,000 ATMs were affected.
Earlier, the Royal Bank of Scotland (RBS) was forced to promise another round of compensation payouts after RBS, Natwest and Ulster Bank were hit by an online banking and ATM blackout which left potentially millions unable to pay for goods and services or receive payments in the runup to Christmas.
To make matters worse, only a day after it claimed to have resolved the problems, NatWest customers were hit by more internet banking issues after a cyber-attack knocked down the bank's website for an hour.
A week later, Ulster Bank customers were stung by another IT glitch.
RBS chief executive Ross McEwan blamed years of IT infrastructure neglect due to investment from his predecessors.
However, within the first few days of 2014, RBS and Natwest credit card customers were hit by more IT problems - but this time the banks insisted that it was Tesco's fault.
RBS blamed Tesco for the IT problem that locked customers' credit cards and left many unable to pay for fuel at the retailer's petrol stations.
RBS insisted that it was Tesco's technology that caused the problem.
In August 2012, RBS revealed that it had put aside £125m to compensate thousands of customers affected by a two-week computer breakdown, which led to millions of customers being stranded without being able to pay outgoing bills.
A year later, the FCA said it would investigate RBS over its 2012 computer failure.