Can HMRC recover an MDR refund if a joint claim is said to be unsigned or invalid?

Introduction

Readers often search for this issue after a stamp duty refund has already been paid and HMRC later opens an enquiry, challenges the claim, or demands the money back. A common problem is where a claim was made for multiple dwellings relief (MDR) on a joint purchase and HMRC later says the paperwork was defective, incomplete, or not properly signed by both purchasers.

This creates two separate questions. First, was the MDR claim valid on its substance? Second, even if the property point is arguable, was the amendment or repayment claim procedurally valid in the first place? Where HMRC says a joint claimant did not authorise the claim, that procedural issue can become decisive.

The Question

A married couple made an MDR-related SDLT repayment claim after buying a property. The claim was submitted through a specialist adviser. HMRC initially processed the claim and the repayment was issued. Later, HMRC investigated the matter and began corresponding with both spouses, apparently treating it as a joint claim.

After that, HMRC changed position and said one spouse had not signed or properly authorised the claim documentation. The couple maintain that both of them did sign the relevant paperwork, although they no longer hold every original document and believe some papers remain with the adviser. They also say the substantive MDR position was carefully considered when the claim was made.

The practical question is whether HMRC can demand repayment on the basis that the joint claim was not properly signed or authorised, and how that fits with the underlying MDR issue.

Nick’s Explanation

Nick’s immediate point was that the documents first provided were not clear enough to analyse properly. In anonymised form, his response was essentially: “The documents are not sufficiently legible for me to determine exactly what they say. Please send the original PDFs, emails, or high-resolution scans so I can review them.”

That is an important tax procedure point in itself. In a dispute like this, the outcome often turns on the exact wording of:

• the SDLT amendment or repayment claim,
• the authority given to the adviser,
• any signature pages,
• HMRC’s enquiry letters, closure letters, and assessment letters, and
• any tribunal correspondence stating appeal rights and deadlines.

Where HMRC alleges that one joint purchaser did not sign, the key evidence will usually be the original signed form, the engagement documents, any letter of authority, and the filing trail showing who submitted the amendment and on whose instructions.

Nick’s approach also reflects a broader legal reality: before deciding whether HMRC is right, you must separate the documentary authority issue from the MDR merits issue. A taxpayer can have a potentially arguable MDR case on the facts of the property and still lose if the claim was not validly made. Equally, HMRC may have difficulty maintaining a signature objection if its own correspondence and processing history show that it treated the matter as a joint claim throughout.

The Law

SDLT is charged under the Finance Act 2003. MDR was contained in Schedule 6B to the Finance Act 2003 before its abolition for most new transactions. Historic claims and enquiries can still give rise to disputes where the transaction took place while MDR was available.

For joint purchasers, SDLT liability and any amendment or repayment position must be considered by reference to the actual purchasers and the return filed for the land transaction. In broad terms:

• an SDLT return is made in respect of the purchasers’ transaction,
• an amendment or repayment claim must be made in the proper form and within the applicable statutory framework, and
• a person acting for taxpayers must have authority to do so.

If HMRC concludes that a repayment was issued on the basis of an invalid amendment or an unauthorised claim, it may seek to recover the amount through the statutory machinery available to it, depending on the procedural route used and the stage the matter has reached.

In many MDR disputes, there is also a substantive legal question about whether the property contained more than one dwelling, or whether part of it was unsuitable for use as a dwelling. On unsuitable-for-use arguments, the threshold is now relatively high following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799. That case reinforces that poor condition, disrepair, or the need for works will not easily take a property outside the normal SDLT dwelling analysis.

Analysis

The correct way to analyse a case like this is step by step.

First, identify exactly what was filed with HMRC. Was this:

• an amendment to an SDLT return,
• a repayment claim following an amendment, or
• some other form of post-completion claim?

The statutory route matters because it affects both validity and HMRC’s powers to enquire into or reverse the position.

Second, identify who the purchasers were. If there were two buyers, a claim affecting the SDLT position of both of them will normally need to reflect that joint ownership and joint tax position. If HMRC says one spouse did not sign or authorise the claim, the first question is whether that is factually true.

Third, gather the authority evidence. Relevant documents may include:

• a wet-ink signature page,
• an electronic signature audit trail,
• an engagement letter with the adviser,
• a specific authority to amend the SDLT return or claim a refund,
• emails confirming instructions from both purchasers, and
• the adviser’s submission records.

If both purchasers clearly authorised the adviser, HMRC may struggle to maintain that the claim was invalid merely because one particular copy of a signature page is missing. But the answer depends on the exact documents and what the statutory requirements were for the route used.

Fourth, examine HMRC’s own conduct. If HMRC opened an enquiry, wrote to both spouses, referred to the matter as a joint claim, and otherwise treated the claim as having been made by both purchasers, that does not automatically cure a legal defect. However, it may be evidentially significant. It may support the taxpayers’ position that HMRC understood the claim to be jointly made and that the alleged signature problem is inconsistent with the filing history.

Fifth, consider whether HMRC’s recovery action is procedurally correct. If HMRC has issued a closure notice, amendment, assessment, or determination, the appeal position depends on the exact document. Deadlines are critical. If a tribunal letter gives 28 days to appeal, that period must be calculated carefully from the date of the appealable decision or the date treated as notified under the legislation and tribunal rules.

Sixth, address the MDR merits separately. Even if the signature issue can be answered, the underlying relief must still be defensible. Many historic MDR claims were made on the basis that a property included an annexe or separate accommodation, or that part of the building was not suitable for use. Those arguments are highly fact-sensitive.

Where the argument is that part of the property was uninhabitable or unsuitable for use as a dwelling, readers should be cautious. The condition thresholds are now relatively high following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799. The Court of Appeal makes clear that the test is demanding. Ordinary disrepair, dated condition, missing items, or the need for refurbishment will often not be enough.

Seventh, if the refund was paid to an adviser rather than directly to the taxpayers, that does not by itself determine the legal position between the taxpayers and HMRC. HMRC will usually pursue the taxpayers if it says the repayment was not due, even if the funds first passed through an agent or claims company.

Outcome

The practical conclusion is this: HMRC can seek to recover an MDR refund if it says the claim was invalidly made or the relief was not due, but whether it is entitled to do so depends on the exact statutory route, the original signed authority, the filing history, and the appeal documents.

If the dispute is about a missing spouse’s signature on a joint claim, the case will often turn on documentary proof. If there is credible evidence that both purchasers authorised the claim and HMRC itself dealt with the matter as a joint application, that may provide a basis to challenge HMRC’s position. But if the original claim or amendment was not validly authorised, that procedural defect can be fatal even before the MDR merits are considered.

On the substantive MDR side, any argument based on the property being uninhabitable or not suitable for use must now be tested against the stricter approach confirmed in Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799.

Practical Steps

Anyone in this position should do the following as quickly as possible:

• obtain the original SDLT return, amendment, and repayment claim in full;
• obtain all engagement letters, authorities, signature pages, and electronic signing records from the adviser;
• collect all HMRC letters, especially enquiry notices, closure notices, assessments, and appeal-right letters;
• create a timeline showing when the claim was filed, when the refund was paid, when HMRC opened its enquiry, and when any appealable decision was issued;
• check the appeal deadline immediately and file a protective appeal if necessary;
• separate the procedural issue of authority/signature from the substantive issue of MDR eligibility;
• if the claim relied on separate dwelling status, gather plans, photographs, valuation evidence, and contemporaneous purchase documents;
• if the claim relied on uninhabitability or unsuitable-for-use arguments, test that evidence carefully against the high threshold confirmed by Mudan.

Where documents are unclear, poor-quality photographs are not enough. Original PDFs, scans, and email chains are usually essential.

Conclusion

A paid SDLT refund is not necessarily the end of the matter. HMRC may revisit MDR claims and may challenge both the legal basis of the relief and the validity of the paperwork used to obtain it. In a joint-purchaser case, the existence and quality of the authority evidence can be as important as the property facts themselves. If HMRC alleges that one spouse did not sign, the dispute must be tested against the original documents and the statutory procedure, not assumptions.

Legal References Used

• Finance Act 2003
• Finance Act 2003, Schedule 6B
• 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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