Challenge 
Mansion tax appeal: how to challenge or appeal your band
From April 2028, homes in England worth £2m or more will pay the High Value Council Tax Surcharge, often called the mansion tax. Your band depends on your home's value at April 2026, and there is no marginal relief: reaching a threshold means the whole higher charge. If your home is placed in the wrong band, you can challenge it with the Valuation Office and then appeal to the Valuation Tribunal. Here is how the proposed mansion tax appeal process works, and what to do now.
By Simon Dredzen, active in the prime central London property market for over two decades · Reviewed 8 November 2026
The bands and charges
| Value at April 2026 | Yearly charge from 2028/29 |
|---|---|
| £2m to under £2.5m | £2,500 |
| £2.5m to under £3.5m | £3,500 |
| £3.5m to under £5m | £5,000 |
| £5m or more | £7,500 |
The charges rise with inflation (CPI) each year from 2029/30. They are separate from your council tax band (A to H).
Key dates
See also our full timeline, step by step.
- April 2026: the valuation date. Every home is valued as it stood then.
- By 1 November 2027: under the Finance Bill, the Valuation Office must send each council the list it proposes, and the council must publicise it. The list shows each chargeable home and its band, not its exact value. Check it early: under the proposals you can query factual errors, such as the wrong floor area or property type.
- 1 April 2028: the first list is compiled and the charge starts. An initial 8-month window is proposed for challenging your band.
- 1 April 2033: the first revaluation. Under the Finance Bill, new lists follow every five years (2038 and so on).
How a mansion tax appeal works
The proposed process has two stages: a challenge to the Valuation Office, then, if needed, an appeal to an independent tribunal.
- Check the draft list when it is published, find your band, and query any factual errors.
- Challenge your band with the Valuation Office within the window, with your evidence of the home's April 2026 value.
- The Valuation Office responds, proposed within 4 months.
- Appeal to the Valuation Tribunal for England within 3 months of that decision if you disagree.
- Keep paying meanwhile. Bills are refunded or adjusted if you win.
If the question is whether you should pay at all, for example because you are not the legal owner, that goes to your local council instead. There is no time limit for this kind of challenge, though you will need evidence, and the council is proposed to reply within 2 months. Its decision can also be appealed to the Valuation Tribunal.
The Finance Bill gives the Valuation Tribunal power to order the list to be altered, a liability decision to be reversed, or a penalty to be quashed, with the detailed rules set by regulations. Valuation officers also have powers to inspect homes. In its response of 28 October 2026, the government confirmed this two-stage route and said the Valuation Office will publish guidance on how bands are decided and the types of evidence it accepts, and will explain the evidence behind each decision. The challenge windows above remain proposals until that guidance and the legislation are published.
Evidence to gather for a band challenge
- Completed sales of similar homes close to April 2026, ideally in your building or street, checked against HM Land Registry records
- An accurate floor area: an overstated size is a common cause of overvaluation
- Your home's condition at April 2026, with dated photographs: evidence that is hard to rebuild once you renovate
- Drawbacks such as a short lease, high service charges, a busy road, no outside space or a lower-ground floor
The consultation proposed excluding estate agent estimates and property website valuations. The Valuation Office will publish guidance on the evidence it accepts and how it assesses it.
An example from Chelsea
By Simon Dredzen. Illustrative figures, not a real case.
Take two flats of 1,200 sq ft in the same Chelsea mansion block. One is on the second floor, with a lift, good light and a long lease. The other is on the lower-ground floor, with less natural light, and needs modernising.
| Second-floor flat | Lower-ground flat | |
|---|---|---|
| What a buyer might pay | £1,900 per sq ft: £2.28m | About 20% less: £1.82m |
| Correct band | £2m to £2.5m: £2,500 a year | Under £2m: no charge |
| If a model values both at the building's average of £1,750 per sq ft (£2.1m) | Same band | Wrongly charged £2,500 a year, about £13,000 to 2032/33 |
A computer model may pick up the address and floor area but miss the floor level, the light and the condition. The owner of the lower-ground flat would challenge with sales of other lower-ground flats in the block or nearby, a measured floor plan, and dated photographs showing the flat as it was in 2026. The same applies to an upper-floor flat with no lift, a short lease, or a home that needs substantial work.
What to do now
- Check your home's likely band with our free checker.
- Start an evidence folder: floor plan, photographs, surveys, lease and comparable sales.
- If your home is near a threshold, get a free personalised preview or book a free consultation.
Questions
Can I appeal my mansion tax band?
Yes, under the proposals. The draft list, due by 1 November 2027,, will let you check your band early and, under the proposals, query factual errors. Formal band challenges are proposed to open when the surcharge starts in April 2028, using evidence of your home's value at April 2026. If you disagree with the Valuation Office's answer, you can appeal to the Valuation Tribunal for England.
When can I challenge my mansion tax valuation?
An initial 8-month challenge window is proposed, opening when the surcharge starts in April 2028. After that, you have 6 months from receiving any new band. The details are proposals and may change, so check GOV.UK when the draft list is published.
What evidence counts in a mansion tax challenge?
Under the proposals, completed sales of similar homes around April 2026 and examples of similar homes in a different band. The consultation proposed excluding estate agent estimates and property website valuations; the Valuation Office will publish guidance on what it accepts. An accurate floor area, your home's condition at April 2026 and drawbacks such as a short lease or a busy road also matter.
Do I keep paying while I challenge?
Yes. Bills are due while a challenge or appeal is under way, and are refunded or adjusted if you win.
Is a mansion tax challenge the same as a council tax band challenge?
No. Your council tax band (A to H) is based on 1991 values and is challenged separately. The mansion tax uses four bands based on April 2026 values: £2m to under £2.5m, £2.5m to under £3.5m, £3.5m to under £5m, and £5m or more.
Based on the HM Treasury consultation on the High Value Council Tax Surcharge (closed 14 July 2026), the government's Summary of Responses (28 October 2026) and House of Commons Library briefing CBP-10934. The process, dates and rules are proposals and may change. This is general information, not tax, legal or valuation advice.