London Cyber Attack Threatens to Hold Up Thousands of Home Sales

A “sophisticated, criminal cyber attack” is threatening to hold up thousands of home sales in two of London’s richest boroughs.

Westminster City Council and the Royal Borough of Kensington and Chelsea have been unable to process local authority searches since November when a cyberattack disrupted their services and forced them to activate emergency plans. Local authority searches — which provide information about a property and its surrounding area including flood risk and new development — are an essential part of the homebuying process, and neither council has so far provided a time frame for resolution.

“If you’re buying with a mortgage, you’ll need a local authority search to secure the loan — you can’t proceed without them,” said Nick Gregori, head of research at LonRes. Even “if you’re a cash buyer and not subject to mortgage due diligence, it’s prudent to take them out because no home purchaser wants to be hit by unexpected surprises later down the line,” he added.

The U.K. faced a spate of damaging cyberattacks last year. Marks & Spencer Group Plc and the Co-op supermarket chain had their stores and online sales disrupted by hackers over the summer, while car manufacturer Jaguar Land Rover had to shut down production for more than a month following a crippling cyberattack in August.

“We know this is frustrating and will work as hard as possible to tackle the backlog once our systems are safely restored,” Elizabeth Campbell, leader of Kensington and Chelsea Council said in an emailed statement. “Systems are being turned back on carefully” with advice from the NCC Group, Met Police and National Cyber Security Centre, she added.

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A Westminster City Council spokesperson said they are working round the clock to restore systems “safely,” adding they “anticipate resuming processing as soon as possible.”

Councils are local government organizations that provide residents with waste collection, education, social care, housing and other services. The two affected London boroughs share some technology infrastructure.

Westminster and Kensington and Chelsea averaged a combined 350 home transactions per month between 2021 and 2024, according to an analysis of Land Registry data by LonRes. Kensington and Chelsea’s residential stamp duty bill totaled about £530 million ($728 million) in 2024-2025, the researcher said.

The delays come amid a broader slump in the London market driven partly by hikes to the stamp duty transaction tax and the coming so-called mansion tax on homes valued at more than £2 million. Residential sales above £5 million tumbled 18% in the first three quarters of 2025 from the same period a year earlier, putting them on course for the fewest in a year since 2020, according to broker Savills Plc.

“We have a government that wants to build 1.5 million homes but this is a proverbial spanner in two key boroughs of London,” said Philip Eastwood, an agent at The Buying Solution. “Even once the issue is resolved, there is going to be such a large backlog,” that will continue to delay the completion of local authority searches and home deals, he added.

The impact of the cyber attack on local authority searches “will undoubtedly impact the number of sales that can take place in the borough, and in turn the amount of revenue the borough will be able to generate,” LonRes’ Gregori said.

In November, the U.K. government published research that estimated cyberattacks cost the country £14.7 billion annually.