Do you pay higher rate SDLT if your unmarried partner still owns a property when you buy together?

Introduction

People often ask whether they can avoid the higher rates of Stamp Duty Land Tax (SDLT) when buying a new home with a partner who still owns another property. The answer depends on who is buying, whether either buyer is replacing a main residence, and whether the old home is sold before or after the new purchase completes.

This issue becomes especially important where one or both buyers already own let properties, are living in rented accommodation, and plan to sell former homes but cannot line up both sales in time. A common follow-up question is whether moving back into a former home shortly before sale can turn it into a main residence for SDLT purposes and remove the surcharge.

The Question

An unmarried couple are living in rented accommodation and want to buy a new home together. Each of them owns another dwelling. One of those properties used to be the buyer’s home many years ago but has been let out for a long period. The other used to be the partner’s home but has also been let since the partner moved out.

One property is expected to be sold before or on the same day as the purchase of the new home, but the other may not be sold until later. The couple want to know:

• whether the 5% higher rates of SDLT will apply if only one old property is sold by completion;
• whether the surcharge can later be reclaimed if the remaining former home is sold within 36 months; and
• whether moving back into one of the old properties shortly before sale would allow the purchase to be treated as a replacement of a main residence, so that the higher rates do not apply at all.

Nick’s Explanation

Nick’s reasoning was that the outcome turns mainly on the structure of the purchase and on who still owns what at completion.

He explained that if both buyers dispose of their existing properties before or on the same day as the new purchase completes, the higher rates should not apply. In anonymised form, his point was:

“If both of you have disposed of your respective properties by the date of completion, neither of you will hold another dwelling interest. In that case, the 5% higher rate will not apply.”

He then explained that if the new property is bought jointly and one buyer still owns another dwelling at completion, that ownership is taken into account for the transaction. In practical terms, if only one former property has been sold by completion and the other partner still owns theirs, the surcharge is due on completion.

Nick also identified an important distinction between married couples or civil partners and unmarried couples. Married couples and civil partners are, in many cases, treated as one unit under Schedule 4ZA. Unmarried couples are not automatically treated in the same way merely because they live together.

On the idea of moving back into a former property shortly before sale, Nick’s conclusion was that this would not solve the real problem where the purchase is still being made jointly and the other buyer still owns another dwelling at completion. Even if one buyer could argue that they are replacing a main residence, that does not remove the surcharge if the joint purchaser still causes the higher rates conditions to be met.

He also identified one possible structural alternative: if the purchase were made by one buyer alone, and that sole buyer satisfied the replacement of main residence rules, the other partner’s retained property would not automatically taint the purchase because that partner would not be a purchaser. But that is a different transaction structure and has separate legal and mortgage consequences.

The Law

The higher rates of SDLT for additional dwellings are contained in Schedule 4ZA to the Finance Act 2003.

The broad rule in paragraph 3 is that the higher rates apply where, at the effective date of the transaction, the purchaser has a major interest in another dwelling and the purchased dwelling is not a replacement for the purchaser’s only or main residence.

Where there is more than one purchaser, the rules look at all purchasers. If any joint purchaser causes the conditions to be met, the higher rates can apply to the whole transaction.

Paragraph 8 deals with replacement of only or main residence. Broadly, a purchase can avoid the higher rates if the buyer is replacing a previous only or main residence and the old residence has been disposed of within the permitted period.

Where the old main residence is sold after the new purchase, the surcharge may initially be payable and then reclaimed, provided the statutory conditions are met and the former main residence is disposed of within the relevant 36-month period.

Repayment claims are generally made by amendment of the SDLT return or under section 80 Finance Act 2003, subject to the statutory time limits.

Whether a property is a person’s “only or main residence” is a question of fact. There is no single statutory minimum period of occupation. However, short or contrived occupation may not be enough if, looking at the facts as a whole, the property was not genuinely the person’s main residence.

Analysis

The position can be broken down into the following steps.

First, if the new home is bought jointly, you test the SDLT position by looking at both buyers at completion. If one buyer has sold their former property but the other still owns another dwelling, the transaction may still fall within the higher rates.

Second, if both old properties are sold before or on the same day as completion of the new purchase, neither buyer will own another dwelling at the effective date. In that situation, the higher rates should not apply.

Third, if only one former property is sold by completion and the other partner still owns their property, the higher rates are likely to apply on a joint purchase. That is so even if the retained property is on the market, temporarily vacant, or was once the partner’s home.

Fourth, if the retained property was previously the partner’s only or main residence, a refund may be available later if that property is sold within 36 months of the new purchase and the other statutory conditions are satisfied. This is the usual route where a replacement purchase happens before the old home can be sold.

Fifth, moving back into one former property shortly before sale does not necessarily remove the surcharge. The key reasons are:

• main residence is a factual test, not a box-ticking exercise based only on electoral roll or council tax records;
• brief reoccupation intended only to secure SDLT treatment may be challenged if the occupation is not genuine;
• even if one buyer could establish that they are replacing their own main residence, a joint purchase can still attract the higher rates if the other buyer still owns another dwelling and does not satisfy the replacement conditions.

Sixth, because the couple in this scenario are unmarried and not in a civil partnership, the rules for spouses and civil partners in paragraph 9(2) do not automatically apply simply because they live together. That matters. But if both are named as joint purchasers, both are still relevant to the SDLT test because they are each purchasers in the transaction.

Seventh, a sole-name purchase can sometimes change the SDLT result. If one person alone buys the new property and that person is replacing their only or main residence, the other partner’s separate property ownership does not automatically affect that purchase because the partner is not a purchaser. But this only works if the legal and mortgage arrangements genuinely support sole ownership. Adding the other partner later can itself create SDLT issues.

Eighth, if anyone is considering arguing that a property was not suitable for use as a dwelling, the threshold is now relatively high following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799. Ordinary disrepair, inconvenience, dated condition, or the need for works will often not be enough. That point is not central to this scenario, but it is relevant whenever someone explores whether a property should be ignored because it was uninhabitable.

Outcome

The practical conclusion is as follows:

• If both former properties are sold before or on the same day as the new joint purchase, the 5% higher rates should not apply.
• If the new home is bought jointly and only one former property is sold by completion, the 5% higher rates will usually apply at completion because the other joint buyer still owns another dwelling.
• If the remaining property was the other buyer’s former main residence, the surcharge can usually be reclaimed once that property is sold, provided the sale takes place within 36 months and the claim is made in time.
• Moving back into one old property shortly before sale is unlikely, on its own, to solve the SDLT problem on a joint purchase where the other buyer still owns another dwelling.

Practical Steps

Anyone in this position should work through the following points carefully before exchange and completion:

• Confirm whether the new property will be bought jointly or in one name only.
• List every dwelling interest owned by each proposed purchaser at the intended completion date.
• Identify which property, if any, was each buyer’s only or main residence and when they moved out.
• Check whether the old main residence will be sold before completion or only afterwards.
• If relying on a later refund, diarise the 36-month disposal deadline and the repayment claim deadline.
• Do not assume that short-term reoccupation will automatically make a property a main residence for SDLT purposes.
• If considering a sole-name purchase, check the mortgage position, beneficial ownership, and the SDLT consequences of any later transfer of an interest.
• Keep evidence showing genuine occupation history and the dates of disposal of any former homes.

Conclusion

On a joint purchase, the higher rates of SDLT usually apply if one buyer still owns another dwelling at completion. The cleanest way to avoid the surcharge is for both former properties to be sold before or on completion, or for the purchase to be structured in a way that only a qualifying replacement buyer is the purchaser. If the surcharge is paid because one former main residence is sold later, a refund may still be available if that sale happens within 36 months and the claim is made on time.

Legal References Used

• Finance Act 2003, Schedule 4ZA
• Finance Act 2003, Schedule 4ZA paragraph 3
• Finance Act 2003, Schedule 4ZA paragraph 8
• Finance Act 2003, Schedule 4ZA paragraph 9(2)
• Finance Act 2003, section 80
• Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799

This page was last updated on 22 March 2026.

See all questions and answers categorized in this sitemap. Or use Google site search below.