Property experts have warned that Chancellor John Healey could expand the UK mansion tax in the upcoming October 28 Budget, raising fears of a fresh raid on wealthy homeowners.
The warning follows admissions from Healey last week that the Government is evolving its position on council tax and plans to introduce a top band for extremely valuable properties.
The Chancellor of the Exchequer sets out government taxation policies and public spending plans during the annual Budget presentation to Parliament. Healey refused to be drawn on the specific details of the proposed measures, but industry analysts expect significant changes to high value property taxation.
Property insiders stated that a full council tax revaluation across all housing bands would be complex and expensive. As a result, the Chancellor may consider lowering the mansion tax threshold from £2 million to £1.5 million while increasing existing annual surcharge rates.
Under current rules, annual surcharges on top of standard household council tax bills range from £2,500 to £7,400. Tom Bill, head of residential research at estate agency Knight Frank, said there was a sense of unfinished business on the issue and suggested the Treasury was mulling over additional property levies.
Bill noted that official comments suggest ministers may be leaving the door open to bringing more homes into the mansion tax net. He added that the rates announced in the previous Budget could prove to be introductory rates only.
Budget expansion proposals
Council tax is a local property tax in the United Kingdom based on property value bands, used to fund municipal services such as local roads and public amenities. The mansion tax was introduced in last year's Budget as an additional annual levy on high value residential properties.
When the government introduced the mansion tax last year, officials estimated it would generate £430 million annually. Treasury calculations indicated that 55 per cent of that revenue would come from just four London boroughs: Kensington and Chelsea, Richmond, Wandsworth, and Westminster.
The London boroughs of Kensington and Chelsea, Westminster, Richmond upon Thames, and Wandsworth contain some of the highest concentration of expensive real estate in the country. High demand in central and prime West London keeps property valuations well above national averages.
Critics of the tax have described the projected £430 million annual revenue as the equivalent of a rounding error within total government finances. They argued that after accounting for the legal expenses of property appeals and homeowner objections, the actual net revenue collected would be minimal.
London property impact
Concerns over broader tax charges have been building for months. The Mail on Sunday revealed in July, before Burnham became Prime Minister, that ministers were already discussing expanding the levy to cover thousands more terraced and semi-detached homes in London and the South East of England.
Housing prices in London and the South East are among the highest in the United Kingdom. Because of rapid capital growth over recent decades, standard family homes in these regions frequently fall into elevated tax brackets despite lacking large plots or luxury amenities.
Valuation office inspections
Tensions surrounding the property tax expansion increased following reports that officials from HMRC's Valuation Office Agency could seek entry into private homes to assess their physical condition and value. The disclosure generated a storm of public protest from homeowner groups.
The Valuation Office Agency is an executive agency of His Majesty's Revenue and Customs, responsible for compiling property valuations across England and Wales. Officials assess residential housing to place properties into appropriate council tax bands.
The Valuation Office Agency is currently revaluing homes situated in council tax bands F, G, and H. This assessment work aims to determine which specific properties will become subject to the mansion tax when the new regulations take effect from April 2028.
Treasury projections suggest Healey hopes to raise additional revenue by extending the mansion tax to an extra 70,000 to 100,000 properties nationwide. However, real estate experts warn that the policy could produce unintended economic consequences.
Mortgage and market risks
Charles Curran of estate agency Maskells warned that the proposal could backfire on the Treasury. Curran explained that the Chancellor must remember that extra costs for homebuyers reduce the maximum mortgage amounts lenders will grant.
Curran stated that reduced mortgage availability would put downward pressure on overall house prices. He noted that lower property values would ultimately reduce the total number of homes meeting the mansion tax threshold, thereby shrinking the overall tax yield.
Healey's statements have also raised broader anxiety across the financial sector that the Government is prioritizing policies to appease Left-wing Labour MPs. Market analysts warn that politically driven tax reforms often depress real estate activity and reduce overall tax receipts.
Non dom policy warnings
Financial experts point to recent reforms as evidence of potential revenue shortfalls. The abolition of the non-dom tax regime last year cost the Exchequer up to £4 billion, according to James Quarmby, head of private wealth at law firm Stephenson Harwood.
The non-domiciled tax status historically allowed individuals residing in the United Kingdom whose permanent home was abroad to avoid paying UK tax on foreign income. The Government had previously estimated that tightening the rules on wealthy non-domiciled residents would generate up to £3 billion in extra annual revenue.
Speaking to Knight Frank's Housing Unpacked podcast last week, Quarmby stated that the non-dom crackdown resulted in net losses for the Treasury. He explained that many mobile high-net-worth individuals responded to the tax increases by relocating overseas to countries with more favorable tax structures, such as Italy.
The departure of wealthy residents reduced overall economic activity and lowered consumer spending in luxury sectors. Quarmby noted that the exodus deprived the Exchequer of substantial income tax receipts and stamp duty land tax revenues as demand for high-end residential real estate fell, raising questions over whether upcoming Budget measures will trigger a similar market contraction.
