Chancellor George Osborne has hit corporate purchasers of properties worth over £500,000 with a new 15% Stamp Duty.

It kicked in at midnight, and was likely mainly to affect the purchase of apartments in London through corporate envelopes such as offshore companies, partnerships and trusts.

The timeframe between announcement and implementation reportedly gave some of the capital’s agents a hair-raising few hours as deals were either rushed through or threatened to fall out of bed – or buyers tried to renegotiate prices down below the threshold.

The new 15% Stamp Duty on £500,000-plus homes bought by corporate envelopes – in reality, often very rich individuals – is forecast to bring in £365m to the Exchequer coffers by 2018/2019. Osborne made it clear that the change will not affect homes that are rented out.

The change caught everyone on the hop, including conveyancers and accountants.

Tax specialist Andrew Seddon, head of tax at law firm Towers and Hamlin, said it was completely  unexpected.

He said: “This is the third Budget in a row in which the Chancellor has increased taxes on companies acquiring residential properties and the goal posts have been moved again.

“We now have an unbelievably draconian and complex taxation system for the residential property sector. Non-residents who buy property in the UK provide significant benefits to the economy which do not seem to be appreciated, and one can only hope that the Chancellor has not killed off the mid-range residential property sector at a stroke.”

Companies and other vehicles – quaintly called ‘non-natural persons’ by HMRC – that own properties will also be hit with  an annual ‘wealth’ tax called ATED (annual tax on enveloped dwellings).

This is to be phased in, affecting properties worth £1m or more in 2015, and properties worth £500,000 or more in 2016. Corporate-type owners of properties worth £1m-plus will pay £7,000 a year, and those of £500,000-plus properties will pay £3,500. Such owners will also be hit with 28% Capital Gains Tax on any sale.

Otherwise, industry response to the Budget was mostly the equivalent of a stifled yawn, after Osborne once again did nothing to reform Stamp Duty.

As the Chancellor had announced beforehand, the shared equity part of Help to Buy (available on new houses only) is to be extended until 2020. The more contentious mortgage guarantee part of the scheme is to end on December 31, 2016.

As was also announced before the red box was opened, there is to be a new ‘garden city’ at Ebbsfleet – which critic Simon Rubinsohn, RICS chief economist, said was really a garden village, with just 15,000 homes.

However, Lucian Cook of Savills said that Ebbsfleet was about establishing a model that other local authorities could follow.