Big bank systems crashed for over 800 hours in last two years due to IT outages

Nine of the UK’s biggest banks accumulated over 33 days of IT downtime over the last two years with millions of people affected.

Data received from banks by MPs on the Treasury Committee revealed at least 158 banking IT failures between January 2023 and February 2025, equating to over 800 hours of service unavailability..

Following the recent three-day outage experienced by Barclays Bank customers, which began on payday at the end of January, MPs demanded answers from bank CEOs.

Chief executives at Barclays, Santander, NatWest, Danske Bank UK, Nationwide Building Society, Allied Irish Bank, HSBC, Bank of Ireland and Lloyds Banking Group were asked for information on the scale and impact of IT failures over the past two years. 

The data does not include the recent Barclays crash, but the bank did provide MPs with details of the effect of the outage. It revealed that during the three-day incident 56% of online payments failed due to “severe degradation of mainframe processing performance,” according to the Treasury Committee. Barclays said it will pay between £5m and £7.5m to customers as a result of the outage and in total Barclays could pay out up to £12.5m in compensation due to outages over the two years in scope.

The banks told MPs that systems and internal software malfunctions were common reasons for the IT failures.

Meg Hillier MP, chair of the Treasury Committee, said for families “living pay cheque to pay cheque” banking downtime is “a terrifying experience”.

“The fact there has been enough outages to fill a whole month within the last two years shows customers’ frustrations are completely valid. The reality is that this data shows even the most successful banks and building societies hit technical glitches. What’s critical is they react swiftly and ensure customers are kept informed throughout,” she added.

Last month, Hillier said the closure of high street branches in favour of online banking means bank crashes hit customers harder. “The rapidly declining number of high street bank branches makes the impact of IT outages even more painful; that’s why I’ve decided to write to some of our biggest banks and building societies.”

She thanked banks for their responses and was “reassured” they are taking action to minimise the impact of IT failures on customers.

Barclays Bank reported the most incidents, 33, with Allied Irish Bank, HSBC and Santander next with 32 each. Nationwide Building Society reported 18 outages, NatWest 13 and Lloyds Bank 12. In single figures were Allied Irish bank (9), Danske (5), and Bank of Ireland (4).

NatWest reported the most downtime at 194 hours, followed by HSBC with 176.

Just last week a further payday outage hit banks including Lloyds Bank, Nationwide, TSB and Nationwide, according to outage monitoring organisation Downdetector.

One senior banking IT professional said that if a number of banks experience problems at the same time, it points to a relating factor. “If it’s lots of banks, it makes me think there’s a common denominator, like they’re using a supplier or software that’s shared by multiple banks, because it would be coincidental for several of them to go down on the same day,” he said.

Further pointing to a potential problem with external IT, the expert added that in his experience, banks try to avoid making IT changes at the end of the month. “End of the month is normally a time banks avoid making changes. For example, financing departments inside the banks do not like the risk of chaos at an unprecedented end of the month because they’re doing month-end accounting and don’t want technology problems.”