The UK's banks experience five IT failures a week according to analysis by Which? with RBS and Santander the worst sufferers.
There have been 265 glitches in the last year preventing customers from accessing accounts or making payments.
The majority of these incidents involved internet banking, which accounted for 133 of them, with mobile and telephone banking failures totalling 111 and 90 respectively.
RBS and Santander were involved in 18 of these each, while Starling and M&S Bank managed to avoid suffering a single one.
The analysis also brings some respite for TSB, which was rated among the better performing banks, suffering six glitches.
The beleaguered bank was in the news again last week for another systems issue which prevented customers from receiving payments.
These findings come as Which? launches its Everyday Finance report on the UK's preferred methods of banking. The report finds that six out of 10 UK customers feel it is important to have access to a bank account that can be managed and accessed in a branch rather than solely online.
Which? believe this highlights the importance of consumers continuing to have easy access to cash. Head of money, Gareth Shaw, describes it as "a vital back-up when digital system fails".
In the face of widespread bank branch and cashpoint closures and regular IT glitches, the consumer champion is calling on the next government to introduce legislation that protects cash
Ahead of the December 12th general election, the Labour Party declared in its manifesto that it would ban ATM fees and stop branch closures and create a publicly-owned Post Office bank as part of a re-nationalised Royal Mail.