A mansion tax is a common name for an annual property tax on high value homes, although the term itself is widely regarded as a misnomer.^[1] The tax was only a proposal in the United Kingdom, but proved very controversial and received widespread media coverage. It did not go ahead.

Many US states levy a surcharge on the highest-value homes or have a progressive taxation in their real estate transfer tax system, sometimes referred to as “mansion taxes.”^[2]

In the United Kingdom, the concept of a mansion tax is widely attributed to Vince Cable.^[3] In its original form, proposed in 2009,^[4] Cable suggested that all properties valued at over £1 million would be taxed annually. He raised the proposed threshold to £2 million in January 2012.^[4]

In an accommodation with Coalition partners, the proposal was modified and a 7% rate of Stamp Duty Land Tax was levied on house sales over £2 million, following George Osborne's 2012 budget. In contrast to an annual "mansion tax", this one-off tax is only paid when a property is bought.

Support for the original proposal re-emerged at the Liberal Democrat 2012 conference.

The motion called for "an annual mansion tax on the excess value of residential properties over £2 million as a first step towards wealth taxation designed to reduce inequality". It was passed in a vote of over 200 delegates, with two against.^[5]

Despite this, the Liberal Democrat's coalition government partner, the Conservatives, ruled out the introduction of a Mansion Tax; Chancellor of the Exchequer George Osborne said in October 2012: "We are not going to have a mansion tax, or a new tax that is a percentage value of people’s properties. Before the election they will call it a mansion tax, but people will wake up the day after the election and discover suddenly their more modest home has been labelled a mansion."^[4]

On 14 February 2013, the Labour Party leader Ed Miliband said that he would, if in government, introduce a mansion tax and then re-introduce a ten pence tax rate for low earners.^[6] However, there was no commitment to put this policy into the Labour Party manifesto and there was also criticism of the fairness and practicality of the proposal.^[7] Miliband reiterated this policy proposal at the 2014 Labour Party Conference and it became a firm commitment. Labour claimed the policy would raise £1.2 billion a year which would be used to fund the National Health Service.^[8] Based on an estimated 100,000 homes valued over £2 million, this means each property would be liable for an average bill of £12,000.^[9]

On 20 October 2014 in response to widespread publicity about the proposal, the Shadow chancellor Ed Balls published further details. He confirmed properties valued between £2 million and £3 million would pay £3,000 per annum, but properties over £3 million would pay considerably more.^[10] Commentators have suggested that in order to raise the projected £1.2 billion, the mansion tax payable on homes over £3 million would have to be £28,000.^[11]

In October 2014, the Liberal Democrats abandoned plans for a new tax on high-value homes, opting instead for a change in the existing Council Tax system.^[12] Nick Clegg, speaking on the BBC during the Liberal Democrat Party Conference 2014, said: "I went off, big time, the idea that you have a fixed levy as a percentage over a certain value. The more I looked at it, the more I thought, 'That’s very crude.' It leads to eye-watering amounts of tax being paid. What we should do is go with the grain of the council tax system and apply bands to higher properties."^[4]

On 3 December 2014 George Osborne announced changes to stamp duty. These measures included large increases in tax for more expensive houses. A buyer of a house at £2 million would now have to pay £153,750 in stamp duty. In his speech he alluded to this being his alternative to Labour's mansion tax.^[13]

Critics have said such a policy would hurt pensioners, as according to analysis by the think-tank the Centre for Policy Studies,^[14] almost one third of all properties worth over £2 million have been in the same ownership for over ten years.

The phrase mansion tax has been described as a misnomer as 10% of properties in London valued at £2m-plus are one- or two-bedroom flats.^[15]

After Labour's May 2015 election defeat, Labour leadership candidates began to distance themselves from the policy. Andy Burnham said the mansion tax had been too "symbolic" and played into a public dislike of the "politics of envy". Mary Creagh, another candidate for the leadership, said: "It alienated a whole bunch of people who said we were against them getting on and doing well".^[16]

The tax could be structured in a number of different ways. One possible variant is to limit the scope to non-resident, non-British owners of property. This would be intended to discourage foreign ownership of dwellings and free up housing stock for residents. Such a modification to the mansion tax has been suggested by Mark Field,^[17] an MP in central London, where overseas ownership of property is commonplace. There are perceptions that the high cost of housing in London is in part due to a disproportionate amount of residential property being owned by non-resident, non-tax paying foreigners,^[18] and that a modified mansion tax may alleviate this issue. Limiting the scope in this way would also limit the valuation exercise that the introduction of a mansion tax would require, as fewer properties would be impacted.

• Council Tax
• Land value tax