A £265m house sale in Chelsea has thrust the six-dwelling stamp duty rule under scrutiny, after an investigation found that adding five modest flats to the deal cut the buyer’s tax bill by £18.5m.
The seller was Nick Candy, the billionaire developer and Reform UK treasurer, and the buyer was City hedge fund manager Suneil Setiya. The concern for investors is that the mechanism was built to help landlords buy portfolios, and its use on a single trophy home could prompt a rethink reaching far beyond Chelsea.
How five flats triggered the six-dwelling stamp duty rule
Research by the think tank Tax Policy Associates and investigative news site London Centric found that when Candy, 53, sold grade II listed Providence House in May 2026, the deal also included five flats “worth a few hundred thousand pounds each”.
When six or more dwellings change hands in a single transaction, HMRC treats the purchase as non-residential, which cuts the rate payable by the buyer from 12 per cent to five per cent.
As a result, Setiya paid £13.25m in stamp duty instead of £31.8m, a saving of £18.5m.
Setiya declined to comment. He is understood to believe the right amount was paid as the law requires, that the properties were available from the owner collectively and that his offer was accepted on that basis.
A spokesman for Candy said he was out of the country and would not be commenting.
A rule written for landlords, not trophy homes
Dan Neidle, head of Tax Policy Associates, said such bundling can in theory suit both sides, as a buyer’s saving is typically reflected informally in the seller’s price.
“Stamp duty is paid by the buyer. So as a matter of law every penny of the saving belongs to the buyer, Mr Setiya,” Neidle wrote.
“That often isn’t the economic answer. A buyer facing £32 million of stamp duty will bid less for a house than a buyer facing £13 million. The saving gets shared through the price one way or another.”
Advisers highlighted the tiny value of the flats relative to the mansion. Tim Stovold, head of tax at accountants and business advisers Moore Kingston Smith, said the rule was “intended to be used by landlords acquiring portfolios of properties without the disincentive of large amounts of stamp duty being payable”.
He added: “The situation where 99 per cent of a transaction was made up of a single property and the remaining five properties the balance of 1 per cent of value was never anticipated in the rules.”
Ben Smith, a tax partner at Wilsons solicitors, was blunt. “This case is particularly striking because of the disparity between the stamp duty payable if the house was purchased on its own, or with the five other properties,” he said, adding that it “undoubtedly raises questions as to the effectiveness of the ‘six or more dwellings’ rule and will prompt further calls for stamp duty reform”.
A house with a long tax history
This is not the first stamp duty dispute linked to Providence House. When the property was bought in 2012, Nick’s brother Christian Candy, 52, exchanged contracts at £68m, made the first lease payment, began building works and paid £1.92m in stamp duty.
In 2014 he transferred the property to Nick, who paid the balance of the price and a further £1.92m in stamp duty.
Christian applied for a refund 18 months after the original purchase date. HMRC refused, arguing he should have claimed after 12 months, but in July 2026 a judge at the Upper Tribunal ruled that he should receive it. With interest, the refund came to £2.3m.
Under Nick Candy, the house, set in a two-acre private garden, was reworked in grand country house style, with a 14,000 sq ft basement, a 60ft swimming pool and Europe’s first private Imax cinema.
He lived there with the Australian actress and singer Holly Valance. The couple announced their divorce in 2025, which is likely to have influenced the decision to sell.
What this means for investors
For landlords, the irony is that a rule meant to ease bulk residential purchases is now tied to one of the most eye-catching tax savings in memory. Investors already absorbing the higher stamp duty surcharge on additional homes and wider buy-to-let tax changes have good reason to watch how the Treasury responds.
Advisers expect renewed pressure for reform, adding to a debate that already includes calls to replace stamp duty with an annual property value tax. Any tightening aimed at lopsided deals like this could easily catch genuine portfolio acquisitions too.
Investors planning multi-property purchases should model deals at both residential and non-residential rates and take specialist advice before relying on the rule. If it is narrowed, ordinary portfolio buyers, not billionaires, will feel it most.
