London’s Most Expensive Mansions Aren’t Selling, New Data Shows

London's luxury housing market isn't doing jolly good.

The most expensive properties in the British capital are failing to land buyers, as potential owners grapple with uncertainties regarding the upcoming budget. There were 22 percent fewer transactions in the 12 months to July than the previous year, according to a new report by U.K. real estate firm Knight Frank .

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Only 149 mansions valued at £10 million (roughly $13.2 million) or more have changed hands in the past 12 months, compared with 192 in the prior period. Super-prime sales totaled £2.8 billion ($3.7 billion) in the year to July, marking a 36 percent decline from the £4.3 billion ($5.7 billion) realized in July 2023.

Many buyers are holding off purchasing property due to concerns about the 2024 Autumn Budget that will be shared on October 30, according to Knight Frank. Chancellor Rachel Reeves could announce changes to capital gains tax, inheritance tax, and council tax, among other measures. Prime Minister Keir Starmer has also shared that he may do away with the so-called non-dom system and start taxing the rich on income earned overseas. The prospect of tighter rules and higher taxes is causing some wealthy individuals to leave the U.K. entirely .

"It's the overall sense of uncertainty rather than any single measure that is making some people hesitate," Stuart Bailey, head of London super-prime sales at Knight Frank, said in a statement. "Despite the fact supply levels are good, buyers at this level are very discretionary."

The higher the price, the greater the discretion, Knight Frank notes. The most expensive abodes are proving the hardest to sell: There were just 10 deals above £30 million ($39.7 million), compared with 38 in the previous period.

The good news is that sales are still ticking, albeit at a slower pace. There is no shortage of stellar homes on the market, either. A lavish penthouse in London's legendary Battersea Power Station (pictured above) just hit the market for $40 million, for instance.

"There are obvious risks at the moment, but the super-prime market is still functioning, just at a reduced level," added Paddy Dring, global head of prime sales at Knight Frank. "It's sometimes easy to forget just how attractive London is on the global stage."