HMRC will dispatch valuation officers to properties across the UK to assess whether they exceed £2 million in value and are therefore liable for the new high-value council tax surcharge, commonly referred to as the mansion tax. The charge, initially announced by former chancellor Rachel Reeves in last year's autumn budget, is scheduled to come into force in April 2028, following a consultation that concluded in July.
The levy applies to properties valued above £2 million, with an annual additional charge of between £2,500 and £7,500 depending on the property's worth. Detailed tiered rates reported by The National show owners of properties worth between £2 million and £2.5 million paying £2,500, rising to £3,500 for properties up to £3.5 million, £5,000 for properties up to £5 million, and £7,500 for those over £5 million. The surcharge is separate from council tax and will rise annually with inflation, according to the same report.
How valuations will work
The Valuation Office, part of HMRC, will initially use third-party data and publicly available information to estimate property values. According to the Valuation Office, physical inspections will be necessary where "attributes can only be confirmed internally or a re-measurement is required." Inspectors will carry out internal assessments of properties, recording the size, architectural style, number of bedrooms, bathrooms, and floors, as reported by multiple outlets including City A.M. and The Sun.
Homes valued above £1.5 million may also be reassessed to ensure none are missed, according to Jonathan Russell, head of the Valuation Office, who told MPs in January that valuation professionals will "probably look at houses that have an indicative value of £1.5million just to make sure we're not missing anything," as reported by The Sun and LADbible.
Homeowners who refuse to allow inspectors entry could face a fine of up to £200 and would be committing a criminal offence, as reported by several outlets, including The Sun and Birmingham Live. Under the Local Government Finance Act 1992, intentionally delaying or obstructing a valuation officer could result in a fine of up to £200 on conviction, while failing to provide required information without a reasonable excuse could lead to a fine of up to £500, according to The Sun and Birmingham Live.
The charge is expected to affect around 165,000 homeowners in its first year, surpassing the initial forecast of 120,000, according to the Office for Budget Responsibility as reported by The Sun and others. An additional 45,000 homes will be subject to the levy, with thousands expected to lodge successful appeals, according to the fiscal watchdog as reported by multiple outlets including The National and Hull Daily Mail. The vast majority of affected homes are expected to be in London and the South East, according to The Sun.
Political reaction
The policy has drawn sharp criticism from Conservative politicians. Shadow Cabinet Office Minister Mike Wood told GB News that the Prime Minister, Andy Burnham, was acting like the "Sheriff of Nottingham," predicting that "council tax police" would "invade" family homes. "It's hard to believe that this is something that's seriously being proposed in Britain," he said, adding "I don't know whether 'Orwellian' is the word." Wood also warned that the threshold could be widened over time, bringing more homes into the levy, and pledged that the Conservatives would oppose the proposals in Parliament, according to GB News and Birmingham Live.
Shadow Chancellor Mel Stride condemned the plan as a "sinister assault on civil liberties," saying: "We may have changed prime minister, but it's the same old story with Labour – how can we raise taxes to pay for more benefits?" as reported by LADbible and Daily Express. Shadow Housing Secretary Sir James Cleverly accused the government of "snooping," stating: "This is sinister. Not content with ramping up taxes on hardworking families Andy Burnham and Angela Rayner will send tax inspectors to snoop around people's homes," according to Evening Standard and Daily Express.
Leaders of four London boroughs wrote to the Housing Secretary, arguing: "A home is the centre of family life, not an untapped tax stream," and expressing concern that pensioners living in homes for decades could be forced to sell, as reported by Evening Standard.
Government defense
A government spokesman defended the policy, saying: "The public understands that we are addressing a longstanding unfairness, where a Band D home in Darlington pays more in council tax than a £10m mansion in Mayfair. The Valuation Office has extensive experience valuing domestic property, and will use a wide range of evidence to determine bandings," as reported by Daily Express and Evening Standard. The spokesman added that visits would take place by prior agreement with the owner and in line with the code of practice, according to Daily Express.
Treasury minister Dan Tomlinson confirmed that homeowners would receive contact from the Valuation Office to "arrange a visit," as reported by Birmingham Live and Evening Standard. Junior Treasury minister Dan Tomlinson also said the Valuation Office would contact homeowners to arrange a visit, according to Daily Express.
The government has also pointed to the Valuation Office's experience, arguing it has "extensive experience in valuing domestic property," as reported by Evening Standard. Ministers have confirmed through answers to Conservative parliamentary questions that internal inspections will be carried out, according to Daily Express.
The policy has reignited debate over property taxation in the UK. Some campaigners argue house prices in London are inflated partly due to second homes, while others highlight properties that are rarely visited, suggesting a tax could free up housing stock, as reported by The National. Advocates for overseas owners point out that many are UK-tied individuals, according to the same report.
The charge is due to take effect in April 2028, with the first payments expected in the 2028/29 tax year, according to The Sun.