The surcharge is due to start in April 2028, with the first bills in March 2028. But the value it is based on is the home's value in 2026, and the draft list of homes in scope is due in autumn 2027. The dates that matter most for owners come well before the first bill.
The timeline
| When | What | What owners can do |
|---|---|---|
| November 2025 | Surcharge announced at the Budget. | Nothing yet. |
| 19 May to 14 July 2026 | Consultation on the design. | Closed. |
| 2026 | The valuation year. | Record the home's size and condition, and note sales of similar homes. |
| 28 October 2026 | Budget and government response to the consultation. | Check whether you could qualify for deferral, an exemption or a discount. |
| 2026 to 2027 | Finance Bill 2026-27, then regulations. | Watch for the detail on deferral interest, exemptions and estates. |
| Autumn 2027 | Draft list of homes in scope. | Check your entry and ask for factual errors to be corrected. |
| March 2028 | First bills. | Check the band on the bill. Apply for deferral if you qualify. |
| April 2028 | The surcharge starts. | Pay monthly, over 12 or 10 instalments. |
| 8 months from the start | Initial challenge window. A new owner gets 6 months. | Challenge the band with the Valuation Office, which has 4 months to respond, then appeal to the tribunal if needed. |
| 2033 | First revaluation. | Check the new band. Revaluations then follow every five years. |
Why 2026 matters more than 2028
Every home will be valued as it stood in 2026. By the time a bill arrives, that year will be two years in the past. Photographs, measurements and details of nearby sales are far easier to gather now than later, and they are what any correction or challenge will rest on.
What could still change
These dates come from the government's response to the consultation and its Budget documents of 28 October 2026. They become law through the Finance Bill 2026-27 and the regulations that follow, and Parliament can still amend the Bill. We will update this guide and the updates page if anything moves.
Also asked
When is the first mansion tax bill?
Councils are due to issue the first bills in March 2028, for the year starting in April 2028.
When will I find out if my home is in scope?
The Valuation Office plans to publish a draft list of homes in scope in autumn 2027. It may contact some owners earlier to check details about their home.
Last checked against the government's Budget documents and consultation response on 30 October 2026. The surcharge is being legislated in the Finance Bill 2026-27 and is not yet law. Some detail is still to come in regulations.