Does the 5% SDLT surcharge apply if I buy in my sole name but my spouse already owns another property?

Introduction

Many buyers assume that if they purchase a home in their sole name, only their own property ownership matters for Stamp Duty Land Tax (SDLT). That is not always right. For the higher rates of SDLT on additional dwellings, married couples and civil partners are often treated as a single unit. This catches people who are buying a main residence in one name where the other spouse already owns a share in another dwelling.

This issue commonly arises where a spouse owns part of a family property, an inherited property, or a property occupied by a relative. The key question is whether that existing interest means the new purchase is treated as an additional dwelling for SDLT purposes.

The Question

A buyer plans to purchase a new home for £550,000 as their only and main residence. The purchase will be in the buyer’s sole name, and the mortgage will also be in that sole name. The buyer does not currently own any residential property.

However, the buyer’s spouse already owns a 50% share in another residential property worth about £350,000. That other property is occupied by the spouse’s parent. The spouse remains on the title and mortgage. The spouse has not sold a former main residence within the previous three years, and the couple are UK resident for SDLT purposes.

The buyer wants to know whether the 5% higher rates surcharge applies, whether first-time buyer relief is available, and whether keeping the spouse off the new title and mortgage avoids the surcharge.

Nick’s Explanation

Nick’s answer was clear: the higher rates apply.

In anonymised form, his reasoning was:

• For SDLT higher rates, spouses are generally treated as one unit.
• HMRC looks at whether either spouse owns another residential property at the end of the transaction.
• It does not matter that the new property is being bought in one spouse’s sole name.
• The surcharge is normally avoided only where the purchase replaces a previous main residence.
• On these facts, there has been no disposal of a previous main residence within the relevant period.

Nick also pointed out an important distinction between first-time buyer relief and the higher rates rules. A reader may come across HMRC manual SDLTM29845 and think a non-purchasing spouse’s ownership does not matter. But that manual passage is about first-time buyer relief, not Schedule 4ZA’s higher rates rules. The tests are different.

Using the figures provided, Nick calculated SDLT on a £550,000 purchase as:

• Standard residential SDLT: £17,500
• Residential SDLT with the 5% surcharge: £45,000

His conclusion was that SDLT of £45,000 would be payable on those facts.

The Law

The higher rates for additional dwellings are set out in Schedule 4ZA to the Finance Act 2003. Broadly, the surcharge applies where, at the end of the day of the transaction:

• the buyer has a major interest in the purchased dwelling;
• the purchased dwelling is not subject to a lease with more than 21 years left to run in a way that takes it outside the rules;
• the buyer owns a major interest in another dwelling worth £40,000 or more; and
• the purchase is not a replacement of the buyer’s only or main residence.

For married couples and civil partners living together, Schedule 4ZA contains special deeming rules. In broad terms, one spouse’s property interests can be attributed to the other for the purpose of deciding whether the higher rates apply. That is why buying in one name alone does not necessarily avoid the surcharge.

The replacement of main residence exception is also central. In simple terms, the surcharge may not apply if the buyer is replacing a previous only or main residence, usually by disposing of it within the permitted period. If there has been no qualifying disposal of a former main residence, the exception is not available.

First-time buyer relief is governed by different provisions in Finance Act 2003. It has its own eligibility rules and should not be confused with Schedule 4ZA. A point made in HMRC guidance on first-time buyer relief does not override the separate spousal rules for the higher rates surcharge.

If a case turns on whether a property was uninhabitable or not suitable for use as a dwelling at the effective date of transaction, the current threshold is relatively high following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799. Ordinary disrepair, dated condition, or the need for works will often not be enough.

Analysis

Applying the rules step by step:

1. The new property is a dwelling and is being acquired for £550,000. So the transaction is within the normal SDLT residential regime.

2. The buyer will own the new property at the end of completion. That satisfies the first condition for the higher rates test.

3. Although the buyer does not own any other property personally, the buyer’s spouse owns a 50% share in another dwelling worth more than £40,000. Because spouses living together are generally treated as one unit under Schedule 4ZA, that existing property interest is taken into account.

4. It does not matter that the spouse will not be on the new title or mortgage. The higher rates test is not avoided simply by leaving the spouse off the purchase documents.

5. The next question is whether the purchase replaces a previous only or main residence. On the facts given, neither spouse has disposed of a former main residence within the relevant period. The spouse’s existing share in the other dwelling is not being sold as part of the purchase, and it is not described as a former main residence that has been disposed of.

6. Because there is another counted dwelling at the end of the transaction and no qualifying replacement of a main residence, the higher rates apply.

The same facts also create difficulty for first-time buyer relief. Relief is not available where the purchase is caught by the higher rates rules in this way, and in any event a buyer should be careful not to rely on guidance that deals with a different relief and a different legal test.

On the figures used here, the SDLT calculation was stated as £45,000 with the surcharge, compared with £17,500 at standard residential rates.

Outcome

Where one spouse buys a new main residence in their sole name, but the other spouse already owns a share in another residential property, the 5% SDLT surcharge will usually apply unless the transaction qualifies as a replacement of a previous only or main residence.

On the facts described here:

• the spouse’s existing 50% share in another dwelling counts;
• buying in sole name does not prevent the surcharge;
• there is no qualifying replacement of a main residence; and
• the SDLT payable is therefore the higher amount.

Practical Steps

If you are assessing your own position, work through these points carefully before exchange or completion:

1. List every residential interest owned by you and your spouse or civil partner, including partial shares, inherited shares, and properties occupied by relatives.

2. Check whether any of those interests are major interests in dwellings worth £40,000 or more.

3. Ask whether either of you has disposed of a former only or main residence within the relevant time frame so that the replacement exception may apply.

4. Do not assume that buying in one name, or keeping one spouse off the mortgage, changes the SDLT result.

5. Be cautious about transfers before completion. A sale, gift, transfer to a company, or trust arrangement can create separate SDLT, Capital Gains Tax, mortgage, and anti-avoidance issues.

6. If you are considering whether a property is not suitable for use as a dwelling, compare the facts against the stricter approach now reflected in Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799.

7. Check HMRC’s SDLT manual and the legislation itself, especially where first-time buyer relief and higher rates are being discussed together, because they are separate regimes.

Conclusion

For SDLT higher rates, spouses are often treated as one economic unit. So if your spouse already owns another dwelling, your purchase in sole name can still be treated as an additional dwelling. Unless the purchase genuinely replaces a previous only or main residence, the 5% surcharge is likely to apply.

Legal References Used

• Finance Act 2003
• Finance Act 2003, Schedule 4ZA
• HMRC SDLT Manual, SDLTM29845
• Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799

This page was last updated on 22 March 2026.

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