Can you claim SDLT back if you bought a house and later converted it into an HMO?

Introduction

A common question in Stamp Duty Land Tax (SDLT) is whether tax can be reclaimed where a buyer purchased an ordinary house and then carried out substantial works, such as converting it into a house in multiple occupation (HMO). Many people hope that the scale of the works means the property should have been treated as non-residential, which would usually attract lower SDLT rates.

In most cases, that argument is difficult. The key issue is the condition of the property at the effective date of the transaction, usually completion. If the building was still suitable for use as a dwelling at that point, residential SDLT rates normally apply, even if major alterations were planned or later carried out.

The Question

A buyer purchased a three-bedroom house in March 2023 for £182,000. After purchase, the property was converted into a six-bedroom HMO. The buyer wants to know whether SDLT can now be reclaimed on the basis that the property should have been taxed at non-residential rates rather than residential rates.

Nick’s Explanation

Nick’s view was that there was unlikely to be a valid SDLT reclaim on these facts. In substance, his explanation was that a three-bedroom house will normally be treated as suitable for use as a dwelling unless it had serious and fundamental defects at completion.

He explained that if a property genuinely falls outside the category of a dwelling, non-residential SDLT rates can apply. On the figures given, that would have made a significant difference:

• Residential SDLT: £5,460
• Non-residential SDLT: £640
• Potential difference: £4,820

However, he also pointed out that recent case law has made it much harder to argue that a property was not suitable for use as a dwelling. In practical terms, unless the property had defects so serious that it could not realistically be lived in as a dwelling at the relevant date, a reclaim is unlikely to succeed.

The Law

SDLT is charged under the Finance Act 2003. Whether residential or non-residential rates apply depends on the nature of the property at the effective date of the transaction.

For SDLT purposes, a building is generally treated as residential property if it is used or suitable for use as a dwelling, or is in the process of being constructed or adapted for such use. The question is not what the buyer intended to do with it later. The question is what the property was, and what condition it was in, at completion.

There has been substantial litigation on the meaning of “suitable for use as a dwelling”. Earlier cases sometimes encouraged taxpayers to argue that disrepair, missing facilities, or planned redevelopment meant a building was not suitable for use as a dwelling. More recent authority has narrowed that argument considerably.

In an uninhabitable or not suitable for use case, the condition thresholds are now relatively high following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799. The court made clear that the test is demanding. Ordinary disrepair, dated condition, or the need for renovation will not usually be enough. The defects generally need to be fundamental.

Analysis

The analysis usually works in four steps.

1. Identify the property as it stood at completion.

   Here, the property was a three-bedroom house when bought. That strongly suggests it was residential in character.

2. Ask whether it was suitable for use as a dwelling at that date.

   If the house could still be occupied as a home, even if it needed repair, modernisation, or significant improvement, it will usually remain a dwelling for SDLT purposes.

3. Ignore later works except as background.

   The fact that the buyer later converted the house into a six-bedroom HMO does not usually alter the SDLT treatment on purchase. SDLT is assessed by reference to the state of the property at the effective date, not by what it became afterwards.

4. Consider whether there were fundamental defects.

   A reclaim would only have real prospects if, at completion, the property had defects so severe that it was not realistically suitable for residential use. After Mudan, that is a high bar. Missing items, poor condition, or a need for extensive works will not automatically satisfy it.

On the facts described, there is nothing to suggest the house had the kind of fundamental and irremediable defects that would take it outside the definition of a dwelling. A later HMO conversion, by itself, does not support a reclaim.

Outcome

On these facts, the practical answer is that an SDLT reclaim is unlikely to be available. A house bought as a normal dwelling will usually be taxed at residential rates, even if the buyer later undertakes a major conversion into an HMO.

The only realistic basis for a reclaim would be evidence that, at completion, the property was not suitable for use as a dwelling under the now stricter legal test. That is difficult to establish and, following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799, considerably harder than many buyers assume.

Practical Steps

If you are assessing a possible SDLT reclaim in a similar case, the sensible steps are:

• Check the exact completion date and the SDLT return submitted.
• Gather evidence of the property’s condition at completion, including survey reports, photographs, contractor reports, valuation evidence, and mortgage records.
• Ask whether the defects were truly fundamental, rather than simply matters of repair, refurbishment, or upgrading.
• Separate later development works from the SDLT position at purchase. Later conversion into an HMO does not usually change the original tax treatment.
• Review the purchase against current case law, especially the stricter approach to “not suitable for use as a dwelling”.
• Take specialist SDLT advice before submitting any reclaim, because weak claims can lead to delay, rejection, and possible HMRC scrutiny.

Conclusion

Buying a house and later converting it into an HMO does not, by itself, create a right to reclaim SDLT. The key question is whether the property was suitable for use as a dwelling at completion. In most ordinary house purchases, the answer will be yes, and recent case law means the threshold for arguing otherwise is now high.

Legal References Used

• Finance Act 2003
• 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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