Editor's note: This brief was summarised by The Property AI Newsroom from a report by The Negotiator. Read the original article for full details.

Mansion Tax Set for 2028: Valuation and Appeals Challenges Ahead

The Government’s Mansion Tax, officially called the High Value Council Tax Surcharge, is scheduled to take effect in April 2028. The tax will apply to properties in England valued at £2 million or more, with fixed annual charges based on property value bands.

According to The Negotiator, the tax bands are set at £2,500 per year for properties valued between £2 million and £2.5 million, £3,500 for those between £2.5 million and £3.5 million, £5,000 for £3.5 million to £5 million, and £7,500 for properties above £5 million. The Government plans to use comparable sales and other information to determine property values. However, the article highlights that establishing accurate valuations may be challenging, especially for high-value properties with few comparable sales or those sold via company shares rather than direct asset sales.

The report notes that the thresholds between tax bands could lead to disputes, as small differences in valuation may result in significant changes to the annual tax bill. The Office for Budget Responsibility (OBR) expects around one in five affected homeowners to appeal their valuations, with an estimated 165,000 properties initially subject to the tax. This could result in approximately 33,000 appeals, and if the OBR’s estimate that about 40% of appeals succeed is accurate, more than 13,000 valuations could be overturned or altered.

The article suggests that this process will require the involvement of surveyors, valuers, lawyers, estate agents, and tribunals, creating a significant administrative burden. It also notes that valuation authorities may have powers, subject to safeguards, to seek access to properties for internal inspections if necessary.

For letting agents and inventory clerks, the introduction of the Mansion Tax may lead to increased demand for property valuations, documentation, and evidence to support or challenge assessments. The administrative processes and potential for appeals could impact workflows and require additional expertise in high-value property transactions.