Mansion tax valuations
"With the new mansion tax set to apply to properties valued over £2 million—using April 2026 values—we’re here to help you get prepared early. Our expert valuations give you the clarity and confidence to plan your finances, budget effectively, and be ready to challenge any government assessment if needed."
- Dan Knowles FRICS, Managing Director and RICS Registered Valuer
Our Managing Director, Dan Knowles FRICS, was the chartered surveyor the HomeOwners Alliance consulted to explain how mansion tax valuations will work — you can read his guidance in their guide to the High Value Council Tax Surcharge.
The ‘mansion tax’, band by band
From April 2028, homes in England valued above £2 million face an annual surcharge — the High Value Council Tax Surcharge — charged on the owner, on top of existing council tax. Your liability is based on the property’s value as at April 2026.
Proposed annual charge by property value
The inspection gap — why the VOA’s figure may be wrong
We expect that nearly all of these valuations will be carried out by the Valuation Office Agency without anyone visiting the property — a desktop exercise built on assumptions about its size, condition, layout and comparable values. Those assumptions may be accurate. They may also be some way off, and an overstated assumption can push your home into a higher band and a larger annual charge. An independent valuation from an RICS Registered Valuer who has actually inspected the property gives you the evidence to check the VOA’s figure — and to challenge it if it is wrong.
These are the rates as currently proposed and remain subject to government consultation.
Why act now?
Timing is everything
The closer your valuation is carried out to April 2026, the more accurately it will reflect true market conditions at the relevant date. Relying on outdated figures from a year or two earlier risks an inaccurate assessment — and could leave you unprepared.
Strengthen your position
A recent, independent valuation gives you credible evidence if you need to challenge the VOA’s assessment. It’s much harder to dispute a valuation if you don’t have up-to-date, professional documentation.
Plan with confidence
Knowing your likely tax bracket ahead of time allows you to make informed decisions, whether you’re considering selling, remortgaging, or simply want peace of mind.
What we offer in London and surrounding counties
Expert, timely valuations
Our RICS-qualified surveyors provide reports based on the latest market evidence, ensuring maximum relevance for your needs.
Support for challenges
Our reports can be used to support your case if you need to challenge the VOA’s valuation, or even to pre-empt their assessment if government guidance allows.
How it works
Accurate assessment
We inspect your property and prepare a detailed, evidence-based report.
Actionable results
You receive a clear, client-friendly report to use for planning or as evidence if required.
Why Websters Surveyors?
- ✓RICS-qualified experts
- ✓Professionally designed, clear reports
- ✓Personal support at every step
- ✓Rigorous reports, backing up our conclusions to help in the event of a challenge to the tax payable
Ask us for a valuation as soon as possible and hold it ready for if and when you need it. Best case — you’ll have a report prepared as close to the April 2026 valuation date as possible, ready to help you challenge a tax band. Worst case — you’ll have a better idea of what the tax is likely to be, which will help you budget for a later date.
Consultation status: The government launched its consultation on the scheme on 19 May 2026, closing on 14 July 2026. It covers the reliefs and exemptions that will apply, a deferral scheme for those unable to pay immediately, and the design of the appeals process — and is also exploring a possible additional premium for non-resident owners. We are monitoring announcements and will update this page as details are confirmed.
Mansion tax: frequently asked questions
What is the mansion tax?
The mansion tax is officially called the High Value Council Tax Surcharge (HVCTS). It applies to residential properties in England valued above £2 million and is charged annually on the owner, in addition to existing council tax, from April 2028. Annual charges range from £2,500 to £7,500 depending on the value band.
When does the mansion tax start, and which date is my property valued at?
The surcharge is payable from April 2028, but liability is based on your property’s value as at April 2026. That April 2026 reference point is why an accurate, independent valuation taken close to that date is so important.
How much is the mansion tax?
The proposed annual charges are: £2,500 for properties valued £2m–£2.5m; £3,500 for £2.5m–£3.5m; £5,000 for £3.5m–£5m; and £7,500 for properties above £5m. The thresholds are expected to rise each year in line with CPI inflation from 2029–30.
Who carries out mansion tax valuations?
The Valuation Office Agency (VOA) is expected to run a targeted valuation exercise to identify properties in scope. The majority are likely to be desk-based assessments using an automated valuation model rather than physical inspections. Fewer than 1% of homes in England are expected to fall within scope, concentrated in London and the South East.
Can I challenge my mansion tax valuation?
Yes. High-value homes are often unique and lack directly comparable sales, and desk-based models can over-value them, so valuations may be open to challenge. An independent RICS Registered Valuer’s report gives you credible, well-evidenced grounds to dispute the VOA’s figure if you believe it is too high.
Should I get my own valuation now?
If your property is near or above £2 million, obtaining an independent valuation referenced to April 2026 puts you in the strongest position to challenge the VOA’s assessment later — or simply to budget with confidence. Acting close to the reference date means your evidence reflects true market conditions at the relevant time.
How much does a mansion tax valuation from Websters cost?
Our mansion tax valuation reports start from £850 + VAT, depending on property value and complexity. Contact us for a fixed quote.