The new levy on expensive homes is expected to impact London and the wider South East most heavily, due to the high concentration of properties that would fall within the proposed new tax band. The measure is to be introduced as part of a "smorgasbord" approach to tax rises, necessitated after the government reportedly reversed its plan to increase income tax rates.
What is the proposed mansion tax?
The core proposal, which has been consistently detailed in reports of a potential mansion tax, involves an Annual Ad Valorem Levy.
- Threshold: The tax is expected to apply to residential properties valued over £2 million, although there have been rumours that the threshold could be as low as £1.5 million.
- Rate: There will likely be an annual 1% levy on the portion of the property's value that exceeds the £2 million threshold.
- Target Revenue: Labour is reportedly targeting approximately £1.2 billion in revenue from this measure.
The Chancellor is reportedly urging Labour MPs to highlight that the Budget's expected tax rises, estimated to be around £20 billion in total, are aimed at ensuring those with the broadest shoulders should pay the most.
Example: An owner of a home valued at £3 million would face an annual tax charge of £10,000 (1% of the £1 million value above the threshold), or close to £800 monthly. A property valued at £2.5 million would incur an extra £5,000 a year.
The payment deferral mechanism
It is also rumoured that a mansion tax could include a payment deferral mechanism to soften the political and social impact of the tax. This would allow certain homeowners, particularly those considered "asset-rich, cash-poor" (such as retirees who have seen their property value soar but live on limited income), to delay paying the annual charge.
Instead of paying the levy annually in cash, the deferred amount plus interest would be recorded as a debt against the property, which must then be paid when the home is eventually sold or transferred.
Who will be affected?
The impact of the tax would be geographically concentrated due to the nature of the possible £2 million threshold.
- London and South East: Just over 60% of homes valued over £2 million are in London, with just under 20% in the South East. This means a significant majority of the tax burden will fall on these two regions. In some parts of London, this threshold encompasses standard family homes.
- Homeowners: The tax is aimed at property wealth but will impact more than just the "super-rich." It will also hit long-term homeowners, who may face immediate cash flow problems without the deferral option.
There are also reports that the government may target properties with a lower threshold, possibly over £1.5 million, which would significantly increase the number of homes affected, particularly in London.
Accompanying property tax changes
To maximise revenue and broaden the base, the annual levy is expected to be accompanied by other targeted property tax reforms:
- Capital Gains Tax (CGT) reform: The government is reportedly considering removing or limiting the Private Residence Relief (PRR) exemption on the sale of a main home for higher-rate taxpayers where the property value exceeds a high threshold, possibly £1.5 million. This would tax the profit made on the sale of a primary residence.
- Council Tax: Media reports suggest that the Chancellor is also considering raising more tax from Council Tax bands F, G, and H.
Property market concerns
Experts warn that the introduction of the new annual levy carries a significant risk of causing property market stagnation among high-value properties and a mansion tax threshold could create a valuation cliff-edge. This is where properties valued marginally above the threshold become much less attractive than similar homes just below the tax-free line, potentially causing downward price pressure on homes priced slightly over £2 million as sellers attempt to avoid the annual charge.
The Chancellor will set out the final fiscal plans and the definitive details of any mansion tax, if there is one, in the Budget on 26th November. For the latest insight on what could be included in the Autumn Budget, check out our article 'Budget 2025 Predictions and rumours'.
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