Homeowners facing the UK government’s new mansion tax will have approximately six months to appeal against the decision before it comes into effect, it has emerged.
The methodology for deciding valuations is due to be announced before the end of this year. Owners will be told by next autumn whether their homes are deemed to be above the £2 million mark at which the charge is introduced.
HM Revenue and Customs has then built in a period to allow for appeals before the system goes live in spring 2028.
Owners who dispute the valuation of their home will be given time to check and challenge the charge, which was introduced by former chancellor Rachel Reeves in last year’s budget.
Owners would be expected to pay £2,500 a year for properties worth £2 million to £2.5 million, and £3,500 for properties worth up to £3.5 million.
Properties between £3.5 million and £5 million would incur a charge of £5,000 annually, while those worth more than £5 million would face a £7,500 levy. The surcharge, officially named the high value council tax surcharge, is separate from the council tax and would rise annually with inflation.
It is expected to affect around 200,000 homes or 1 per cent of properties, mostly in London and the south-east of the country. There have been complaints that the £2 million threshold in London is too low, as it could easily apply to a terraced house rather than a mansion.
John-Paul Marks, the chief executive of HMRC, told the Treasury Committee this week that 300 extra staff would be needed within the Valuation Office to implement the tax.
Committee chairman Meg Hillier said there was a “lot of worry out there that people will have inspectors visiting their home, checking their extension” for valuations.
Mr Marks said valuations would be done using AI and publicly available data such as property sales and registry, with inspections in some cases, usually at the request of a homeowner who wished to challenge a decision.
Visits would be a last resort, and only with the agreement of the homeowner, he said. Home visits currently take place in disputes over council tax banding.
“Want to make valuations a confident, trusted process that people can engage with and see the methodology and data sources that they’re drawn on,” Mr Marks said, with the intention that would reduce the number of appeals.
“The list would be published in advance, so that customers would have a chance to check it, to challenge it if for any reason they think it’s not accurate and ultimately appeal if there was a dispute.”
The Valuation Office has previously said inspections would be required where “attributes can only be confirmed internally or a re-measurement is required”.
Anyone who “intentionally delays or obstructs” a valuation officer carrying out their duties faces a £200 fine, ministers said last month. Failing to provide information without a “reasonable excuse” could result in a fine of up to £500.
James Cleverly, the Conservatives’ shadow housing secretary, said families faced tax inspectors “snooping around their gardens and inside their homes, to justify hiking taxes on them”.
The government has said the tax was “addressing a long-standing unfairness, where a Band D home in Darlington pays more in council tax than a £10 million mansion in Mayfair”.
It said: “The Valuation Office has extensive experience valuing domestic property, and will use a wide range of evidence to determine bandings.”
