A power failure at a Google Cloud data centre in London disrupted online banking, payment services, and other digital platforms on Tuesday, exposing the risks businesses face when critical operations depend on shared cloud infrastructure.
Revolut, Lloyds Bank and HSBC were among the financial institutions affected, while Royal Mail, Rightmove and HM Courts and Tribunals Service also reported problems during the disruption.
Google’s preliminary incident report revealed that the outage began when a power interruption affected its europe-west2-b availability zone. According to the company, the failure lasted six hours and ten minutes and affected multiple Google Cloud services across its London region.
How a Power Failure Disrupted Google Cloud Services
Google’s investigation found that the facility’s backup power system failed to take over after the electricity supply was interrupted. The data centre initially relied on its uninterruptible power supply batteries while emergency diesel generators were supposed to start.
However, a fault involving the facility’s primary and backup programmable logic controllers prevented the generators from starting automatically. When the UPS batteries eventually ran out, physical servers, network equipment, and storage systems in the affected zone lost power.
Apart from the aforementioned affected companies, the disruption also affected workloads running in other parts of the London region. According to Google, some customers using infrastructure outside the affected zone experienced unexpected problems as the outage triggered additional failover and delays in processing queued workloads.
Eventually, Google engineers isolated the affected infrastructure, restored a stable power supply, and gradually brought services back online. The company reported that more than 99% of its Compute Engine virtual machines were healthy by the end of the main recovery period.
The company also said a full incident report would follow after its investigation was complete.
Banks and Other Services Report Disruptions
The outage affected several financial services that customers rely on for everyday transactions. Revolut reported problems with card payments, cash withdrawals, and other banking functions. Lloyds Bank and HSBC also acknowledged issues affecting some customers’ access to online services.
While Revolut reassured customers that their money and data remained safe, the reported disruption still raises concerns on service availability and transaction processing, especially when there’s no confirmed evidence in the available reports that customer information had been compromised.
Other affected services included Rightmove, where some users experienced problems with logged-in features, and HM Courts and Tribunals Service, which reported issues with the video platform used for remote hearings in England and Wales.
The range of affected organisations shows how a single infrastructure incident can disrupt businesses operating in different sectors. Companies may run separate applications and serve different customers, but they can still depend on the same underlying cloud services.
UK and EU Regulators Have Already Flagged These Risks
The Google Cloud outage comes as UK and European regulators step up oversight of technology providers that support the financial sector.
In July 2026, the UK designated Google Cloud, Microsoft, Amazon Web Services, and Oracle as critical third-party suppliers to the financial sector, bringing them under direct regulatory oversight from July 13. The Bank of England, Prudential Regulation Authority, and Financial Conduct Authority will jointly supervise the providers, including assessing their resilience and requiring them to report major incidents.
The move followed similar action by the European Union in November 2025, when regulators designated 19 technology companies, including Google Cloud, Amazon Web Services and Microsoft, as critical third-party providers under the Digital Operational Resilience Act. The framework allows regulators to directly supervise technology companies whose services are important to the financial sector.
Both measures reflect concerns that a disruption at a major technology provider could affect several financial institutions at the same time.
Why Enterprise Infrastructure Needs Better Resilience
This incident also raises questions about how businesses prepare for failures involving their cloud providers. Companies often distribute workloads across availability zones to reduce the risk of local infrastructure problems bringing their services offline.
However, Google’s incident showed that disruption in one zone can also affect workloads elsewhere when systems redirect traffic or struggle to process additional requests. And this raises questions on the overreliance of enterprise infrastructure on one cloud provider.
In this case, businesses need to understand which applications depend on specific cloud regions, how much capacity remains available during an outage, and whether their recovery arrangements have been tested under realistic conditions, especially for organisations in banking, payment, or other essential services.
Google’s final report should provide more information about the steps it will take to prevent a similar disruption.
