New tax rules which come into force in April could leave some homeowners with a bill of £7,000 if their property is partly or wholly owned by a company or partnership.

The 2014 budget reduced the threshold for dwellings that fall within the Annual Tax for Enveloped Buildings (ATED) - what used to be called the Annual Residential Property Tax - from £2m to £1m.

The threshold will come down again in 2016 to £500,000 bringing thousands more properties throughout the UK into the tax bracket and forcing owners to submit an ATED return.

Sue Crossley, from The Country House Company in Hampshire, which handles the sale and letting of high quality rural properties throughout the south, said many owners were unaware of the new tax burden, adding: “This is going to be a shock for a lot of people. This change was tucked away in the small print of the 2014 budget but now it is actually coming true for a lot of people.”

Most residential properties are owned directly by individuals, but in some cases they may be owned by a company or a partnership with a corporate member. Then the dwelling is said to be ‘enveloped’ because the ownership sits within a corporate wrapper or envelope.