HMRC is examining up to £645m in potential additional tax liabilities involving some of the UK’s largest property companies, new figures show.
The amount under consideration for the 2025-26 financial year has jumped 40% from £461m a year earlier.
Law firm Bryan Cave Leighton Paisner (BCLP) obtained the figures through HMRC technical notes and a Freedom of Information request.
The data covers investigations by HMRC’s Large Business Directorate, which oversees the tax affairs of around 2,000 of the UK’s biggest businesses. These include major listed property groups.
The £645m figure does not represent tax that companies necessarily owe.
Instead, HMRC uses “tax under consideration” to estimate the maximum additional liability that could arise before completing a full investigation.
The sharp increase nevertheless points to greater scrutiny of tax affairs across the property sector.
BCLP said the rise comes as HMRC expands its compliance operation.
The tax authority recruited more than 1,600 compliance officers during 2025-26. It plans to add a further 5,500 officers by 2030 as part of efforts to increase tax compliance and revenue collection.
HMRC generated more than £50bn in compliance yield during 2025-26, passing the £50bn mark for the first time.
However, BCLP said the tax authority has also become less willing to provide businesses with clarity on the tax treatment of transactions before they take place.
Figures obtained through a Freedom of Information request show HMRC rejected 41% of requests for confirmation of tax treatment in 2025-26. This was the highest proportion in five years.
The rejection rate was even higher for corporation tax queries.
HMRC rejected 63% of corporation tax requests, more than double the previous rate of around 25% to 30%.
