UK government to deploy HMRC inspectors for new mansion tax

The UK government is preparing to deploy HM Revenue and Customs (HMRC) valuation inspectors to private residences to enforce a new “mansion tax,” officially known as the High Value Council Tax Surcharge. The levy, which targets properties exceeding a £2 million threshold, is expected to result in an annual surcharge between £2,500 and £7,500.

Under the proposed plan, HMRC agents will be granted powers to conduct internal inspections to accurately determine property values. This marks a shift from previous suggestions that the valuation process would rely primarily on third-party records and public data. Homeowners who refuse entry to inspectors or fail to provide requested information could face criminal penalties, including fines of up to £500 for obstruction or failure to comply without a “reasonable excuse.”

The surcharge is anticipated to take effect in April 2028. Conservative opposition leaders have criticized the move, labeling the inspectors “council tax police” and arguing that the policy threatens the privacy and aspirations of homeowners, including pensioners and working families.