In the 2025 Autumn Budget, the UK government announced the introduction of a new annual property levy formally called the High Value Council Tax Surcharge — widely referred to as the “mansion tax.”

How much will homeowners pay — and when?

The surcharge will follow a tiered “bands” system depending on property value. The currently proposed bands are:| Property value (2026 valuation) | Annual surcharge |

£2.0 m – £2.5 m  = £2,500

£2.5 m – £3.5 m  = £3,500

£3.5 m – £5.0 m = £5,000

£5.0 m+ = £7,500

Who will be affected — and how many homes?

* The tax is aimed at the top end of the residential market. Government estimates suggest fewer than 1% of properties in England will fall above the £2 million threshold.

* Geographically, the bulk of impacted homes are expected to be in London and the South East, although high-value homes elsewhere are also in scope.

* For the average home buyer or homeowner, this means the vast majority will not be affected.