UK investment banks lost £2.4m as a result of major IT outages in the past 12 months, with network issues, human error, and outdated or legacy systems being the main causes.

The latest survey from financial services IT consultancy GFT, which was conducted by Censuswide, also found that the average IT outage lasts over one hour and costs the investment bank affected £600,000. The survey received responses from more than 200 IT decision-makers at investment banks in the UK.

Krista Griggs, global account director, Capital Markets at GFT, said: “As scrutiny from regulators, counterparties and clients intensifies, investment banks face growing pressure to minimise disruption and safeguard business continuity.”

Financial penalties from regulators and the loss of customers are increasing the total cost of IT outages. But GFT’s research found there are obstacles that get in the way of investment banks making their IT infrastructures more reliable. It reported that 39% of the IT decision-makers questioned said that regulatory complexity was a barrier to resilience, while 37% cited internal resistance to change and 28% highlighted a shortage of internal skills.

Looking forward, the IT decision-makers questioned said that cyber threats, AI integration challenges and legacy systems will be potential major causes of outages.

In the wider banking sector, the costs of these problems are huge. Data received from nine of the UK’s biggest banks by MPs on the Treasury Committee, revealed at least 158 banking IT failures between January 2023 and February 2025, equating to more than 800 hours of service unavailability.

Barclays Bank reported the most incidents (33) during the period and reported it could pay out up to £12.5m in compensation due to outages over the two years in scope.

Allied Irish Bank, HSBC and Santander were hit by 32 incidents each, while Nationwide Building Society reported 18 outages, NatWest 13 and Lloyds Bank 12. NatWest reported the most downtime at 194 hours, followed by HSBC with 176. The banks told MPs that systems and internal software malfunctions were common reasons for the IT failures.

But it is not always internal failures that cause outages, with finance firms today heavily reliant on IT firms, particularly large cloud service providers. A recent IT problem at Amazon Web Services (AWS) caused a 14-hour outage on 20 October. It originated in the public cloud giant’s US-East-1 datacentre region in North Virginia and caused large-scale disruption to a host of companies across the world, including UK finance giant Lloyds Banking Group.

The Financial Conduct Authority UK has warned that it would like to strengthen its control over third-party suppliers to the wider sector, such as AWS.

According to a report in the Guardian, Sarah Pritchard, the FCA’s deputy chief executive, when asked whether it was worrying for the regulator that companies like Amazon are not designated as critical third-party suppliers to the finance sector, which means they avoid regulatory oversight, said: “We would like to see the system strengthen. And we stand ready to supervise jointly with the PRA [Prudential Regulation Authority] and the Bank of England when there is a designation that’s made.”

Read more on IT consultancy

• 
  

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

  By: Karl Flinders

• 
  

  MPs demand bank bosses come clean over IT outages following Barclays crash

  By: Karl Flinders

• 
  

  NatWest group shutters 32 more branches as digital shift continues

  By: Karl Flinders

• 
  

  NatWest offers online banking customers free security services

  By: Alex Scroxton