An outage at Google’s cloud services in the UK has caused widespread disruption, hitting courts and leaving millions of customers unable to access or send cash at banks including Lloyds, HSBC and Revolut.

Google blamed a “power event” for the failure at its London-based Cloud computing operations on Tuesday, which affected its “europe-west2-b zone”.

The US tech company said services were starting to come back online as of 1pm London time, and were back online for most customers by 3pm, but not before critical financial transactions and legal proceedings were disrupted.

That included the video system used by defendants, lawyers and other parties to attend court hearings remotely across England and Wales, which failed to work throughout the morning.

The issue was believed to have delayed several hearings, as the system is often used for defendants who are in custody, but need to attend court.

Meanwhile, bank customers at high street lenders and leading digital bank Revolut were left in limbo through the first half of the day as services including card payments, cash withdrawals and transfers were disrupted.

The City regulator, the Financial Conduct Authority, confirmed it was in touch with Google and seeking more information about the outage.

Halifax, owned by Lloyds Bank, said on X that some of its customers had been unable to log in via the app and online.

Revolut said its app was down because of a “service disruption” affecting several services, but insisted that customers’ funds and data were safe. The outage was affecting new and current customers, hitting its sign-up, sign-in, card payments, transfers, ATM withdrawals and cryptocurrency services.

In a statement, Revolut said: “We are currently experiencing a service disruption affecting multiple services. We can confirm that all our customers’ money and data are safe. We’ve been working to fix the issue since it was identified this morning and apologise to anyone affected and for any inconvenience caused.”

A spokesperson for Lloyds originally said that customers were having issues with “certain online services” on Tuesday morning but that they were aware of “similar issues affecting other organisations”. By the afternoon, the banking group issued an update saying: “We understand the root issues have been resolved, so we expect to all our services back to normal soon.”

HSBC customers had also been complaining online that they were struggling to access their accounts. A spokesperson for the bank said: “We are aware that some customers are experiencing difficulties accessing our services. We would like to apologise for any inconvenience and continue to monitor the situation, which is also affecting other organisations.”

This outage will be the first major test for the FCA and Bank of England, since the City watchdogs were handed powers to regulate Google and other rival services that have been supplying “critical” cloud services to UK financial firms this summer.

The property portal Rightmove was also reportedly affected by the Google cloud outage, and NewsThump, the satire and spoof news website, was struggling to load. Reports suggested Royal Mail and DPD had also suffered disruption.

Google said: “We will publish an analysis of this incident once we have completed our internal investigation. We thank you for your patience while we’re working on resolving the issue.”