Millions of people across the UK were left unable to pay for goods, withdraw cash or move money on Tuesday after a failure at Google’s cloud computing operations in London knocked banks, courts and other services offline for much of the day.

Google blamed a “power event” affecting one of the data centre zones that make up its London region, identified by the company as “europe-west2-b”. It said services began coming back online at about 1pm London time and had been restored for most customers by 3pm, but not before critical financial transactions and court proceedings were disrupted.

Banks hit

The digital bank Revolut was among the worst affected. Its app went down because of what it called a “service disruption” affecting sign-up, sign-in, card payments, transfers, ATM withdrawals and cryptocurrency services for both new and existing customers.

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

Customers of high street banks also reported problems. Halifax, part of Lloyds Banking Group, said some customers had been unable to log in through its app and online banking. Lloyds initially said it was aware of issues with “certain online services” and of “similar issues affecting other organisations”. By the afternoon it said: “We understand the root issues have been resolved, so we expect all our services back to normal soon.”

HSBC customers also complained of being unable to access their accounts. A spokesperson 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.”

Court hearings delayed

The failure also brought down the video system used by defendants, lawyers and other parties to attend court hearings remotely across England and Wales. The system did not work throughout Tuesday morning and is believed to have delayed several hearings, as it is often used for defendants held in custody who need to appear before a court without being transported.

Other organisations were also reported to have been affected, including the property portal Rightmove and the parcel firms Royal Mail and DPD, while the satirical news site NewsThump struggled to load.

A first test for regulators

The outage is the first major test of new powers handed to the Bank of England and the Financial Conduct Authority (FCA) this summer to oversee technology companies that provide “critical” services, such as cloud computing, to UK financial firms. Under the regime, companies such as Google, Amazon and Microsoft can be designated as critical third parties and made to meet standards on resilience.

The FCA confirmed it was in contact with Google and was seeking more information about the incident. 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.”

Why one fault spread so far

Cloud providers divide each region into several zones, separate data centres with independent power and cooling, so that a fault in one should not take down the whole region. Many firms run their systems across several zones to protect against exactly this kind of failure, but some services depend on a single zone, or on suppliers that do.

The concentration of banking, retail and public services on a small number of cloud providers has worried regulators for years. When one provider suffers a problem, the effects can cascade through many businesses at the same time, as happened when a faulty software update from the cybersecurity firm CrowdStrike disrupted airlines, hospitals and broadcasters worldwide in July 2024.

What customers can do

Consumer groups advise customers who were charged fees, missed payments or suffered losses because of the disruption to contact their bank and keep records of any costs. Banks have previously offered compensation after major outages, and customers who are not satisfied with a bank’s response can take a complaint to the Financial Ombudsman Service.

Experts also recommend that households keep a second way to pay, such as a card from a different bank or a small amount of cash, so that a single outage does not leave them unable to buy essentials.

Questions are likely to be asked in Parliament about how a power fault at a single site could leave so many people without access to their money, and whether the new oversight regime is strong enough to prevent a repeat.