Mansion Tax Calculator - High-Value Council Tax Surcharge

From April 2028, homes worth £2 million or more face an annual high-value council tax surcharge - the so-called mansion tax - of between £2,500 and £7,500 depending on value. Check your band and the yearly cost.

What is the mansion tax and how much will I pay?

The "mansion tax" is the nickname for the High-Value Council Tax Surcharge, a new annual charge confirmed at the Autumn Budget 2025 that takes effect from April 2028. It applies to residential properties in England valued at £2 million or more and is paid on top of your normal council tax. Depending on your property's value, the surcharge runs from £2,500 to £7,500 a year, so a home worth £2.2 million would pay an extra £2,500 annually, while one worth £6 million would pay an extra £7,500.

This is not a tax on buying a home and it does not replace your existing council tax band. It is a standalone yearly charge layered over the council tax you already pay, aimed at the highest-value homes in the country.

Key facts at a glance

• Official name: High-Value Council Tax Surcharge (the "mansion tax").
• Announced: Autumn Budget 2025; starts April 2028.
• Who pays: owners of homes valued at £2 million or more.
• How much: a fixed annual surcharge of £2,500, £3,500, £5,000 or £7,500 depending on the band.
• On top of council tax: it is charged in addition to your normal council tax, not instead of it.
• Valuation date: based on a property valuation around 2026.
• Reach: the government expects fewer than 1% of homes in England to be affected.
• Revenue: projected to raise about £430 million a year.
• Uprating: the charges rise each year in line with CPI inflation.
• Status: final valuations and thresholds remain subject to consultation.

How the mansion tax calculator works

Our mansion tax calculator does one job and does it clearly: it takes the estimated market value of your home and tells you which of the four surcharge bands you fall into, then shows the annual charge you would pay from April 2028. Because the High-Value Council Tax Surcharge is a flat amount per band rather than a percentage of value, the maths is simple once you know your valuation - but the band you land in makes a large difference to the bill.

You enter your property's estimated value. The mansion tax calculator compares that figure against the £2 million entry threshold and the three upper boundaries (£2.5m, £3.5m and £5m), then returns the matching fixed surcharge. If your home is worth less than £2 million, you pay nothing extra and only your ordinary council tax applies. The valuation that matters is the one set around 2026, not necessarily what you paid years ago or what an estate agent quotes today.

What are the mansion tax bands for 2026/27?

There are four mansion tax bands, each with a fixed annual surcharge. The table below sets out the value ranges and the high value council tax surcharge attached to each. These are the figures confirmed at the Autumn Budget 2025 for the charge that begins in April 2028; they will be uprated by CPI inflation in later years.

Notice that the surcharge does not scale smoothly with value. The gap between the bottom band and the top band is £5,000 a year, but within a band every owner pays the same flat amount. That is why a precise valuation matters so much: a home valued at £2.49 million pays £2,500, while one valued at £2.55 million pays £3,500 - a £1,000 difference driven by a small movement across a single threshold.

How does the mansion tax differ from stamp duty and council tax?

People often confuse the mansion tax UK charge with the taxes they already know. The High-Value Council Tax Surcharge is separate from Stamp Duty Land Tax, which is a one-off tax paid only when you buy a property. If you buy a £2.5 million home you pay stamp duty once at purchase; the mansion tax then applies every year you own it, regardless of whether you ever move. You can model the purchase cost with our stamp duty calculator and the ongoing yearly cost with the mansion tax tool.

It is also separate from the existing council tax bands (A to H in England). Those bands are unchanged by this measure, and the surcharge sits on top of whatever band your local authority already charges. To check your underlying liability, use our council tax calculator. In short: stamp duty is paid when you buy, council tax is your standard annual local charge, and the High-Value Council Tax Surcharge is an extra annual layer for homes at £2 million or more.

This is the heart of the so-called £2 million property tax 2028: an ongoing annual cost tied to ownership of high-value homes rather than to any transaction. If you are weighing up whether to keep, let or sell such a property, it is worth modelling the wider picture - the capital gains tax on property calculator shows what a future sale might cost, while the rental income tax calculator helps if you are considering letting it out instead.

Who actually pays the mansion tax?

The government has been explicit that this is a narrow measure. It expects fewer than 1% of homes in England to fall within the £2 million threshold, concentrated heavily in London and the South East, with the charge forecast to raise around £430 million a year. For the overwhelming majority of households, nothing changes - the surcharge simply does not apply.

The liability attaches to the property's value, so it is the owner of the qualifying home who pays. Because the charge is uprated by CPI inflation each year, the cash amounts in the four bands will gradually rise after 2028, even though the band structure stays the same. If you own a high-value home that you may eventually pass on, it is sensible to consider how the annual surcharge interacts with your wider estate planning; our inheritance tax calculator can help you see the full long-term cost of holding the asset.

What to do if your home is near a band threshold

If your property sits close to £2 million, or near one of the internal boundaries at £2.5m, £3.5m or £5m, the valuation is the single most important number for you - a modest difference in the assessed figure can move you up a band and add £1,000 or more to your annual bill. Here is a practical, step-by-step approach.

• Get a realistic valuation. Use the value as at around 2026, which is the basis the government has signalled. Do not rely on an aspirational asking price or a figure from years ago; aim for an evidenced market valuation from comparable local sales.
• Run the numbers now. Use the mansion tax calculator to see which band you fall into and what the surcharge would be, so the April 2028 start date does not catch you out.
• Keep evidence if you are near the £2 million floor. If a credible valuation puts you just under £2 million, retain the supporting comparables in case your property is assessed for the surcharge.
• Watch the consultation. Final valuations and thresholds are still subject to consultation, so the exact mechanics - including how values are assessed and any appeal route - may change before April 2028. Follow the official updates rather than press speculation.
• Take advice before any drastic action. Do not rush into selling, gifting or restructuring ownership purely to dodge a band. The surcharge is modest relative to the value of the asset, and a poorly planned disposal could trigger far larger capital gains or inheritance tax costs.

For the official position on council tax and the surrounding rules, see GOV.UK guidance on council tax, and for the policy background read the government's Autumn Budget 2025 announcements. Updates as the measure is finalised will appear via official GOV.UK news.

When does the mansion tax start and will it change?

The High-Value Council Tax Surcharge begins in April 2028. The four bands and the £2,500–£7,500 charges were confirmed at the Autumn Budget 2025, but final valuations and thresholds remain subject to consultation, so details could still be refined before the start date. Once it is live, the charges will be uprated by CPI inflation each year, meaning the cash amounts will creep upward over time even though the band boundaries are fixed at launch.

Because this is the mansion tax UK measure most likely to affect high-value homeowners' yearly budgets, the sensible move is to establish your likely band now using a current valuation, then revisit it as the consultation concludes. Knowing whether you are comfortably inside a band or sitting on a threshold puts you in control well ahead of the 2028 deadline.

This article is general information about the High-Value Council Tax Surcharge for the 2026/27 tax year and is not personal tax or financial advice. Final valuations and thresholds remain subject to consultation; always confirm your position against current GOV.UK guidance or with a qualified adviser before acting.

Who should use this calculator

A high-value property surcharge — commonly called a mansion tax — has been proposed in various forms as an annual charge on homes above a value threshold. This estimates the cost at your property value under the banded structures discussed.

The important framing is that this would be an annual charge on an unrealised asset, unlike stamp duty which is paid once on purchase. That distinction is why proposals attract concern about asset-rich, cash-poor owners — particularly pensioners in homes bought decades ago at a fraction of today’s value.

What this calculator assumes

• The surcharge is an annual charge banded by property value, sitting on top of existing council tax.
• The value used is a current estimate rather than an official valuation.
• Bands and rates reflect published proposals, not enacted legislation.

Limitations — what it does not cover

• Whether any such charge is introduced, and at what thresholds — none of this is law.
• How properties would be valued, and how often revalued.
• Deferral schemes for asset-rich, income-poor owners, which most proposals include.
• Appeal rights against a valuation.
• Interaction with council tax, which might be reformed simultaneously.
• Regional effects, which fall heavily on London and the South East.