Do you pay higher Stamp Duty if you buy a new home before selling your flat?

Introduction

A common question in home moves is what happens if someone buys their next home before their current one has sold. This often arises where a buyer needs short-term family help or bridging funds so they can secure a purchase before completing their sale.

In that situation, Stamp Duty Land Tax (SDLT) can become more expensive at the point of purchase because the buyer may temporarily own two dwellings. The key issue is whether the higher rates for additional dwellings apply, and if they do, whether the extra SDLT can later be reclaimed once the old home is sold.

The Question

A homeowner already owns a flat which is on the market. Before that flat is sold, they want to buy a house for £220,000 to live in as their new main residence. A family member is willing to lend the purchase money until the flat is sold.

The question is whether the buyer must pay SDLT at the higher rates when buying the new house, and whether any of that SDLT can be refunded after the flat is sold.

Nick’s Explanation

Nick’s answer was that if the buyer purchases the new home before selling the flat, the higher rates of SDLT will apply at completion because the buyer will then own more than one dwelling.

In anonymised form, his explanation was:

“If the new property is bought for £220,000 before the existing flat is sold, the higher rates of stamp duty will apply. If the former home is then sold within three years of buying the new property, a refund of the higher rates element can be claimed.”

That is the core rule for a replacement of a main residence. The buyer pays the extra SDLT upfront if they still own the previous dwelling on the purchase date, but may later recover the surcharge if the old main residence is sold within the permitted time limit.

The Law

SDLT on residential property is charged under Finance Act 2003. The higher rates for additional dwellings are imposed by Schedule 4ZA to Finance Act 2003.

Broadly, the higher rates apply where, at the end of the day of the purchase:

• the buyer owns an interest in the purchased dwelling,
• the buyer owns an interest in another dwelling worth £40,000 or more, and
• the transaction is not treated as a replacement of the buyer’s only or main residence at that time.

Where a person buys a new home before disposing of their old main residence, the legislation generally requires the higher rates to be paid first. However, if the old main residence is sold within three years of the purchase of the new one, the buyer can usually claim a refund of the higher rates element.

The refund mechanism is part of the statutory scheme for replacement of a main residence. HMRC’s published guidance also reflects this approach.

Analysis

Step 1: Look at the position on the day the new house is bought.

If the buyer completes on the new house while still owning the flat, they will own two dwellings at the end of that day. That is enough to bring the higher rates rules into play unless the old main residence has already been disposed of.

Step 2: Decide whether the purchase is immediately treated as a replacement of a main residence.

If the old home has not yet been sold, the purchase is not normally treated as an immediate replacement for SDLT filing purposes. So the buyer must usually pay SDLT at the higher rates on completion.

Step 3: Calculate the SDLT due on a £220,000 purchase.

On the figures given in Nick’s reply, the total SDLT payable at completion would be £11,000. That reflects the higher residential rates applying to the whole purchase price.

Step 4: Consider whether a refund can later be claimed.

If the flat was the buyer’s previous only or main residence, and it is sold within three years after buying the new house, the buyer can usually reclaim the higher rates element paid because the transaction then falls within the replacement of main residence rules.

Step 5: Consider the claim deadline.

Nick referred to the usual time limit of claiming within 12 months of the sale of the former home. In practice, refund claims must be made within the statutory deadline, which is generally the later of:

• 12 months after the sale of the previous main residence, or
• 12 months after the filing date for the SDLT return for the new purchase.

Step 6: Note what does not change the SDLT result.

The fact that a family member is lending the money does not itself alter the SDLT analysis. The key SDLT question is whether the buyer still owns the previous dwelling at the end of the day of the new purchase.

Step 7: Check whether the old property really was the previous main residence.

The refund is not available simply because another dwelling is sold. The sold property must have been the buyer’s former only or main residence. That is a factual question based on occupation and use.

Outcome

Where a person buys a new home for £220,000 before selling their existing flat, they will usually have to pay SDLT at the higher rates on completion if they still own the flat that day.

If the flat is then sold within three years, and it was their previous only or main residence, they can usually reclaim the higher rates element from HMRC within the applicable time limit.

Practical Steps

• Check whether the flat is the buyer’s current or former only or main residence.
• Confirm whether the flat will still be owned on the completion date of the new house purchase.
• Ask the conveyancer to calculate SDLT on the basis that the higher rates may apply initially.
• Keep records showing that the flat was the previous main residence, such as council tax, utility bills and electoral roll evidence if needed.
• If the flat is sold after the new purchase, note the completion date carefully and diarise the refund deadline.
• Submit the refund claim to HMRC within the statutory time limit once the former home has been sold.

Conclusion

If you buy your next home before selling your current flat, higher SDLT will usually be payable upfront because you temporarily own two dwellings. If the old flat was your previous main residence and you sell it within three years, the extra SDLT can usually be reclaimed.

Legal References Used

• Finance Act 2003
• Finance Act 2003, Schedule 4ZA
• HMRC guidance on refunds of the higher rates of Stamp Duty Land Tax

This page was last updated on 22 March 2026.

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