Mansion Tax Calculator (High Value Council Tax Surcharge)

How to use this calculator

1. Enter what your home would sell for on the open market in 2026. That is the value the surcharge uses, not the price you paid or an asking price.
2. Enter your council tax for the year from your bill. The box starts empty, with a grey example of £4,784, the England average for Band H in 2026–27. Leave it blank to see the surcharge on its own.

The result shows your band, the yearly surcharge, what it adds to each of 12 monthly instalments, and your council tax and surcharge together. If your value is within 5% of a threshold, a line under the result says how much a valuation either side of it would change the bill. The summary tab adds the 10-instalment figure and the surcharge as a share of your home’s value.

Buying a home worth £2m or more? The England & NI Stamp Duty Calculator works out the tax due when you buy it.

What do I need to enter?

• Your home’s value in 2026 — what it would sell for on the open market in 2026, up to £1,000,000,000. The band is picked from this value alone.
• Your council tax a year — optional, up to £100,000, from your bill. Leave it blank to see the surcharge on its own; blank is not the same as £0.

What do the results show?

• Surcharge — the main figure: the flat yearly charge for your band, or £0 below £2m.
• Surcharge band — the band your 2026 value is in, or Below £2m.
• Each month (12 instalments) — the surcharge divided by 12.
• With your council tax — council tax plus surcharge for the year. It shows Not entered if you left council tax blank.
• Next band up — the next threshold and how far your value is from it.
• Summary — adds the 10-instalment figure and the surcharge as a share of your home’s value.

How much is the mansion tax?

The mansion tax is the informal name for the High Value Council Tax Surcharge, announced at the November 2025 Budget. It is a flat yearly charge on homes in England worth £2 million or more, set by which of four bands the home’s 2026 value falls in:

Worked example: a £2,250,000 home. It falls in the £2m to £2.5m band, so the surcharge is £2,500 a year, or £208.33 a month over 12 instalments. With council tax of £4,784, the total is £7,284 a year, or £607 a month.

What if my home is near a band threshold?

The surcharge is not charged on a slice of the value the way stamp duty is. The whole band charge is due as soon as a home crosses a threshold. A home valued at £2,499,000 pays £2,500 a year; one valued at £2,500,000 pays £3,500. At the bottom, £1,999,999 pays nothing and £2,000,000 pays £2,500.

So if your home sits close to a threshold, the valuation matters more than usual. The calculator flags any value within 5% of one. Once the bands are set, owners will have an initial 8 months to challenge their banding, and 6 months after that, in line with council tax.

When does it start, and who pays it?

• From April 2028, in England only. Councils send the first bills in March 2028 and collect the surcharge alongside council tax, on behalf of central government.
• The owner pays, not the occupier. That means the freeholder, or a leaseholder whose lease was granted for more than 21 years. Joint owners are jointly liable; companies and trustees are liable too.
• On top of council tax. Your normal council tax bill carries on as before.
• Valued at 2026 prices. The Valuation Office is valuing homes that may be worth £2m or more. Homes are revalued every five years; the next revaluation is in 2033.
• Rising with inflation. The charges go up with CPI each year from 2029–30.

Which homes are exempt from the mansion tax?

The consultation proposes that these homes pay no surcharge:

• Homes owned by a registered social housing provider
• Purpose-built student halls of residence
• Ministry of Defence housing for the armed forces
• Homes owned by a foreign state to house its diplomats
• Care homes, long-stay hospital accommodation and hospices
• Refuges for people escaping domestic violence
• New builds still owned by the developer, until first sale or 12 months after completion

It also proposes discounts of up to 100% for some homes whose use can change, such as homes tied to a job or owned by a charity. Fewer than 1% of homes in England are expected to be worth £2m or more.

Can I put off paying the surcharge?

The government has proposed a deferral scheme for owners who cannot afford the charge. As consulted on, it would cover your main home where household income is £35,000 or less and savings are £16,000 or less, and some main homes of disabled people. The surcharge would build up, with interest, until the home is sold or changes hands. Second homes and company-owned homes would not qualify.

Is the mansion tax confirmed?

The bands and start date were set out in the November 2025 Budget. A consultation on how the surcharge will work ran from 19 May to 14 July 2026. Exemptions, discounts, the deferral scheme and the appeal rules may still change before the law is made. This calculator follows the published bands and was last reviewed 15 October 2026.

What this calculator does not cover

• Homes in Scotland, Wales or Northern Ireland, where the surcharge does not apply
• Exemptions and discounts, such as tied homes or charity-owned property
• The proposed deferral scheme
• Any extra charge on non-UK resident owners, which the government is still exploring
• Rises with CPI inflation from 2029–30, which are not yet known
• Working out your home’s 2026 value, which is the Valuation Office’s job
• Tax, legal or valuation advice

Disclaimer and sources

This is an estimate based on the bands the government has published. The surcharge is not yet law, and your actual band will depend on the Valuation Office’s 2026 valuation of your home. Check GOV.UK for the final rules, and take advice if a lot depends on the answer.

• GOV.UK: High Value Council Tax Surcharge policy paper
• GOV.UK: High Value Council Tax Surcharge consultation
• GOV.UK: Council Tax levels set by local authorities in England 2026 to 2027
• Local Government Finance Act 1992, section 5 (council tax band proportions)

Frequently asked questions