One in Four Owners Facing the Mansion Tax Would Consider Selling, but Moving Carries Its Own Bill

Some 26% of homeowners surveyed by specialist lender Together would consider selling to avoid the planned mansion tax, according to The Times. The findings bring a new question into the prime-property market: whether an additional annual charge will prompt owners to make a move they had previously postponed.

More than 11% anticipated reducing everyday spending. The report’s estimate of approximately 37,000 potential sellers is an extrapolation, not a count of properties coming to market. Considering a sale is several steps removed from completing one.

For an individual household, however, the question is real. An owner may have substantial equity but a tighter monthly budget than the property’s value suggests. Another may already be considering downsizing and see the surcharge as a further reason to investigate.

The financial answer will differ between those households. A move can reduce debt and release capital, but buying and selling valuable property can involve substantial costs before any annual saving begins.

The Announced Charge Is One Part of the Ownership Budget

The government’s published High Value Council Tax Surcharge framework concerns residential property in England valued at £2m or more in 2026, with implementation planned for April 2028. It sits alongside existing council tax and applies to owners.

The framework provides for inflation-linked increases from 2029–30 and periodic revaluations. Owners should confirm the final administrative arrangements, including any applicable support or relief, before making commitments.

The valuation reference matters. A lower asking price or market estimate in 2027 should not automatically be assumed to remove a property from scope when the announced starting basis is its 2026 value.

For planning purposes, a household should place the anticipated charge beside maintenance, insurance, energy, council tax and mortgage costs. Its importance becomes clearer when assessed against accessible income rather than the home’s headline value.

Moving Solely to Save the Surcharge Can Be Expensive

Consider a hypothetical household selling a £3m main home and buying a £1.8m replacement in England. Assume the old home is sold before or at completion, the replacement qualifies for standard residential SDLT rates and no additional-property or non-resident surcharge applies.

At the current standard bands, SDLT on the £1.8m purchase would be £129,750. That is calculated across the relevant bands, rather than by applying one rate to the entire price.

Now assume a selling-agent fee of 1.5% of the £3m sale price, including VAT, and £10,000 in combined legal, survey and moving costs. These are illustrative allowances, not quotations.

Compared with a £3,500 annual charge, that assumed transaction bill represents more than 52 years of payments at an unchanged amount. This is a simple scale comparison, not a financial forecast: it ignores inflation, discounting, house-price changes and every other benefit or cost of moving.

It nevertheless shows why the annual tax saving alone is an incomplete reason to transact. If the family wants a smaller home, a different location or less debt, those benefits may be considerably more significant.

Downsizing May Reduce Debt Without Releasing Much Cash

Add an outstanding £1m mortgage to the example. Selling for £3m would produce £2m before selling costs and any mortgage redemption charges.

After the assumed £184,750 of total transaction costs and a £1.8m replacement purchase, the household would have approximately £15,250 left. It would own the new home outright, assuming the transaction proceeds as modelled.

That is a substantial change in the balance sheet: the family has removed £1m of debt. But the £1.2m difference between the two property prices has not become £1.2m of accessible savings.

This distinction matters for owners approaching retirement. They may want both a mortgage-free home and a larger cash reserve. The replacement budget needs to be set with both objectives in mind.

Alternatively, the family might consider retaining some borrowing on the new property to preserve cash. That would require a fresh assessment of income, age, term, repayment arrangements and cost. It should not be assumed available merely because the new loan would be smaller than the old one.

The Mortgage May Matter More Than the New Charge

For a homeowner with substantial outstanding debt, a change in mortgage pricing can have a larger annual impact than the proposed surcharge.

On an unchanged £1m interest-only balance, a 0.5 percentage-point difference in interest rate represents £5,000 a year before fees. That calculation is not evidence that a cheaper product is available, but it demonstrates why the borrowing deserves attention within the wider review.

A remortgage comparison should include product fees, valuation and legal costs, early repayment charges and the period for which the new arrangement is expected to remain suitable.

Changing repayment structure needs particular care. Moving from capital repayment to interest-only can reduce monthly payments while leaving the debt outstanding. It does not produce the same financial outcome as reducing the interest rate or paying down the mortgage.

For an owner whose income has fallen, the review may identify a mismatch between property wealth and monthly resources. Borrowing more to cover recurring expenditure can postpone that pressure while increasing future obligations. It needs a sustainable plan, not simply available security.

A Decision to Sell Does Not Set the Completion Date

The survey adds an ownership-cost question to the selling-time issue discussed in Willow’s earlier coverage of slower £2m-plus property sales.

For a homeowner planning a replacement purchase, the practical concern is whether the sale proceeds will arrive when needed. A listing, an offer and an exchange of contracts represent different stages of certainty.

If the family finds its next home first, it may need to consider delaying the purchase, arranging a coordinated chain or investigating suitable borrowing to cover an overlap. Each option has different costs and conditions.

A temporary loan should be assessed against a realistic sale timetable and a lower-price scenario. Interest, fees and two sets of ownership costs can accumulate while the original property remains unsold.

The tax position can also change when the purchase completes first. Higher SDLT rates may apply initially, with any subsequent refund dependent on meeting the relevant conditions. The solicitor should confirm the amount required at completion, rather than the family budgeting only for an expected eventual refund.

A Modest Price Adjustment Can Outweigh Several Years of Tax

On a £3m property, a 2% change in the achieved sale price is £60,000. That is far larger than one year’s surcharge in the illustrative case.

This does not mean a homeowner should refuse a reasonable offer. It means the sale decision should be based on the full economics and personal objectives, rather than a desire to eliminate one annual bill at any cost.

A lower sale price might still be acceptable if the replacement property is also available on better terms. Conversely, a strong selling price may offer little advantage if the next purchase is expensive or requires extensive work.

The useful comparison is the net cost of the move: what is received, what must be repaid, what the replacement costs and how much cash remains.

For owners near a valuation boundary, professional valuation advice can also help establish the facts. Informally lowering an asking price is not a substitute for understanding how the official assessment will operate.

Some Families Will Have Good Reasons to Stay

A home may be close to family, medical support or established community ties. It may also suit the household better than the properties available at a lower price.

If recurring costs are affordable and the mortgage remains suitable, paying an additional charge may be preferable to incurring the costs and disruption of moving. That is a financial and personal judgement, not a failure to respond to the policy.

Others may find the surcharge prompts a useful conversation they had already delayed. A large house might require too much maintenance, retirement may be approaching or the family may want to reduce its concentration of wealth in one asset.

For those households, downsizing can make sense even where the tax saving is a small part of the overall benefit. The recommendation should explain those benefits clearly rather than presenting the move as a simple tax-saving exercise.

Compare Three Complete Plans Before Choosing One

A retain, refinance or move review should begin with the current mortgage statement, repayment terms, accessible savings and a realistic household budget. It should then add professional estimates of property values and transaction costs.

The retain option needs a sustainable ownership budget. The refinance option needs suitable lending terms and an explanation of what changes in the debt. The move option needs net sale proceeds, a realistic purchase budget and a plan for any overlap.

Each should be tested against the family’s expected circumstances over the next several years. Retirement, changing employment, school costs, support for relatives and planned relocation can matter more than the immediate tax headline.

Willow can assess the financing alongside the client’s estate agent, solicitor, tax adviser and financial planner. The objective is a decision the family understands, including what it costs now, what it commits them to later and whether it supports the life they want next.