The proposed surcharge will add a new annual cost to owning a higher-value home. It could also influence how buyers assess affordability and how properties near its thresholds are marketed and negotiated.
Westminster City Council has joined three other London boroughs in asking the Government to reconsider the forthcoming High Value Council Tax Surcharge.
Although commonly described as a “mansion tax”, the charge will not apply only to mansions. Flats, mews houses and long-held family homes could all fall within its scope if their assessed 2026 value is £2 million or more.
So, how will the charge work, how will properties be valued and what could it mean for people buying, selling or owning a higher-value home?
What Is the High Value Council Tax Surcharge?
The High Value Council Tax Surcharge, or HVCTS, is a new annual charge due to take effect in England from April 2028.
It will be payable in addition to existing council tax. The proposed annual charges are:
- £2,500 for properties valued from £2 million to below £2.5 million
- £3,500 for properties valued from £2.5 million to below £3.5 million
- £5,000 for properties valued from £3.5 million to £5 million
- £7,500 for properties valued above £5 million
The charges are expected to rise annually with inflation and will be billed by local authorities alongside the council tax cycle.
The Government estimates that fewer than 1% of homes in England will be affected, but a significant proportion are concentrated in London and the South East. Some of the detailed arrangements have been through consultation and may still change before implementation.
Who Will Pay the Surcharge?
Unlike ordinary council tax, which is generally paid by the occupier, the surcharge will be the responsibility of the property’s legal owner.
For rented property, this means the landlord would be liable even where the tenant pays the ordinary council tax.
For a leasehold home, the long leaseholder would normally be responsible where the lease was originally granted for more than 21 years. This will be relevant to many higher-value London flats.
The surcharge will not be restricted to main residences. Second homes, rental investments and company-owned properties may also fall within its scope.
Why Is Westminster Challenging It?
On 14 September 2026, the leaders of Westminster, Wandsworth, Richmond and Kensington and Chelsea wrote jointly to the Chancellor, asking the Government to reconsider the surcharge.
Their concern is that property value does not necessarily reflect the owner’s income. Long-standing residents may be living in homes that have appreciated substantially without having the income to absorb another annual charge easily.
The councils have also raised concerns about the divisions between the proposed bands and the possibility that affected landlords could try to recover some of the cost through higher rents.
The Government argues that owners of England’s most valuable homes should make a greater contribution towards local government services and that the surcharge will help address inequalities within the existing council tax system.
Why Does This Matter in Higher-Value Property Markets?
The expression “mansion tax” can be misleading, particularly in London.
In W2, W9 and NW8, which form Wendy Obuli Property’s core area, as well as elsewhere across Westminster and neighbouring boroughs, the £2 million threshold may include lateral apartments, mansion-block properties, penthouses, mews houses and family homes.
A property marketed at or above £2 million will not automatically be included. A seller’s asking price or the price shown in a property listing is not the same as the valuation used for tax purposes.
The key figure will be the property’s 2026 value as assessed by the Valuation Office.
How Will Properties Be Valued?
The Valuation Office, which forms part of HMRC, will undertake a targeted valuation exercise.
It intends to examine sales of comparable homes and adjust for differences between them. It will also consider features such as the property’s type, age, size, room count and parking, together with tax, planning and other property data.
An automated model will produce initial estimates, but professional valuers will review the banding decisions. Where a property is unusual or comparable evidence is limited, its individual characteristics should receive greater attention.
Neither an asking price nor one completed sale will determine the band on its own.
General revaluations are expected every five years, with the first after implementation scheduled for 2033. Charges will rise with inflation, while a future government will decide whether the property-value thresholds should also change.
Significant improvements, such as a large extension, will generally be reflected when the home is sold or at the next revaluation, whichever comes first. Owners should not therefore receive an immediate higher charge simply because they improve or maintain their property.
What Could It Mean for Buyers and Sellers?
For buyers, the surcharge will become another part of the overall cost of ownership, alongside council tax, service charges, maintenance, insurance, financing and leasehold costs.
Before purchasing an affected home, a buyer will need to establish which band applies and whether a challenge is underway.
For sellers, the assigned band and annual charge may influence how buyers assess affordability and formulate an offer. Properties close to a threshold could attract particular scrutiny, especially where comparable homes fall into different bands.
If the seller has previously deferred surcharge payments, that debt would remain the seller’s responsibility. Because it would be secured against the property, it would normally be cleared from the seller’s proceeds during the conveyancing process rather than passed to the buyer.
This does not necessarily mean affected homes will become difficult to sell. However, some buyers may account for several years of payments when comparing otherwise similar properties.
Clear, evidence-based pricing will remain important. Buyers and sellers may both need to understand how the band was reached rather than relying on the marketing price alone.
What Could It Mean for Landlords?
A landlord would be liable for the surcharge even where the tenant occupies the property and pays the ordinary council tax.
This creates an additional ownership cost. It would be unwise to assume that the full charge could simply be added to the rent, as rental pricing remains shaped by tenant affordability, competing supply, property condition and prevailing demand.
Landlords considering a purchase near or above the threshold should include the surcharge in their longer-term affordability and yield calculations.
The proposed payment-deferral scheme would not be available for second homes, rental investments or company-owned properties.
What If a Homeowner Cannot Afford It?
The Government proposes allowing some qualifying homeowners to defer payment until the property changes ownership.
The scheme would apply only to a primary residence and would be subject to financial or disability-related eligibility criteria. The final rules have not yet been confirmed.
A deferred charge would not be cancelled. Interest would be added and the debt secured against the property. The owner could repay it earlier, but otherwise the accumulated balance would normally be settled from their proceeds when the home is sold.
Can an Owner Challenge the Band?
Owners are expected to receive an initial eight-month period in which to challenge their first banding.
After that, a standard six-month challenge window would apply when a new band is issued, a relevant change is recorded or a new owner becomes responsible for the property.
The Valuation Office would have four months to respond. If the owner disagreed with its decision, they would then have a further three months to appeal to the Valuation Tribunal.
Grounds for challenge could include the property being placed in the wrong band, being included when it should not be or a material change not being reflected.
Evidence about the property’s characteristics and comparable sales from 2026 may therefore be important.
What Should Owners Do Now?
There is no need to make hurried decisions based on headlines.
Owners of properties that may sit near a threshold can prepare by:
- Keeping accurate records of the property’s size, lease and significant alterations.
- Retaining planning documents and evidence of material differences from comparable homes.
- Following the publication of the draft property list and notification arrangements.
- Checking the assigned band within the applicable challenge period.
- Considering the possible surcharge when planning a future purchase, sale or investment.
Legal, tax or valuation advice may be necessary where individual circumstances are more complex.
What Happens Next?
The eventual market effect will depend on more than the surcharge alone. Mortgage rates, taxation, supply and buyer confidence will continue to influence prices and activity.
Some buyers may treat the surcharge as one ownership cost among many. Others may factor several years of payments into what they are prepared to offer, particularly where a property sits just above a threshold.
It would therefore be premature to assume either that values will fall sharply or that the charge will make no difference.
For homeowners, buyers, sellers and landlords, the most useful response is neither alarm nor dismissal. It is to understand the proposals, follow the remaining decisions and consider the potential annual cost alongside the property’s wider financial picture.
Wendy Obuli Property will continue to follow the development of the surcharge and what it may mean for higher-value homes in London, including W2, W9 and NW8.
Considering a Higher-Value Property Move?
If you are considering buying, selling or reviewing a higher-value property, Wendy Obuli Property can help you assess its current market position and the practical questions surrounding your next step.
This resource provides general information and should not be regarded as legal, tax, financial or valuation advice. The detailed rules may change before implementation, and appropriate professional advice should be sought for individual circumstances.
Read the Government’s High Value Council Tax Surcharge proposals