Can you reclaim SDLT if a sale was delayed because of a misunderstanding and you missed the replacement of main residence deadline?

Introduction

People often ask whether they can recover higher rates of Stamp Duty Land Tax (SDLT) where they bought a new home before selling their old one, but the sale of the old home was delayed for reasons outside their control. A common concern is whether HMRC will accept that the delay was caused by an unexpected problem in the conveyancing process.

This issue usually arises where the buyer paid the higher rates because they still owned their previous home on the day they completed the purchase of the new one, but they expected to sell the old home within the time limit for replacement of a main residence relief. If the sale happened late, the key question becomes whether the statutory exception for delays caused by exceptional circumstances can apply.

The Question

A homeowner bought a new dwelling and paid the higher rates of SDLT because their previous home had not yet been sold. They later sold the previous home, but the sale took place outside the normal permitted period for claiming a refund of the higher rates.

The homeowner says the delay happened because of a mistaken belief during the conveyancing process that a particular listed building completion document was needed before the sale could proceed. They want to know whether that misunderstanding may amount to an exceptional circumstance, and what evidence would be needed to support an SDLT refund claim.

Nick’s Explanation

Nick’s view was that the claim appeared arguable and potentially winnable, provided the evidence clearly showed why the sale was delayed.

In summary, his reasoning was:

• There was already core transaction evidence available, including the SDLT filing record, transfer deed, sale contract and completion statement.
• If the supposed document did not in fact exist, correspondence showing that one side of the transaction believed it was required, or that the other side insisted upon it, could help show that the delay was caused by that misunderstanding.
• The case would be stronger if there were emails or letters between the parties’ conveyancers specifically discussing the missing document and linking it to the delay in exchange or completion.

Put simply, the point is not just that the sale was delayed, but why it was delayed and whether the cause falls within the statutory wording on exceptional circumstances beyond the taxpayer’s control.

The Law

The higher rates of SDLT for additional dwellings are set out in Schedule 4ZA to the Finance Act 2003. Where a person buys a new main residence before selling their old one, they may have to pay the higher rates at the time of purchase.

If the old main residence is later sold, a refund may be available if the sale takes place within the relevant time limit and the other conditions are met. The replacement of main residence rules are also contained in Schedule 4ZA to the Finance Act 2003.

There is a further provision dealing with exceptional circumstances that prevented the sale of the previous main residence within the normal period. In broad terms, that provision can extend the time available, but only where the statutory test is satisfied.

For any argument based on the condition of a property being uninhabitable or not suitable for use as a dwelling, the legal threshold is now relatively high following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799. That authority makes clear that not every defect, disrepair issue or practical difficulty will mean a building is unsuitable for use as a dwelling for SDLT purposes.

Analysis

The analysis usually has four stages.

1. Was the higher rate correctly paid at the time of purchase?

   If the buyer still owned their previous home when they bought the new one, the higher rates were often correctly charged at completion.

2. Was the previous home later sold?

   If yes, the next question is whether the sale took place within the standard refund period. If it did, the claim is usually more straightforward. If it did not, the buyer must rely on the exceptional circumstances rules.

3. Was the delay caused by exceptional circumstances beyond the buyer’s control?

   This is the critical point. A routine delay, a change of mind, chain problems of an ordinary kind, or general conveyancing slowness may not be enough. But if the evidence shows that the transaction was held up by a specific and unusual misunderstanding about a document said to be required for completion, that may support an argument that the delay was outside the buyer’s control.

4. Can the buyer prove the causal link?

   The buyer needs evidence showing not only that the misunderstanding existed, but that it actually caused the sale to complete late. That is why correspondence between conveyancers can be so important. It may show that the parties were ready to proceed but did not do so because one side believed a non-existent or unnecessary document had to be produced first.

In a case like this, the strongest evidence would usually include:

• emails or letters from the seller’s conveyancer referring to the supposed document;
• emails or letters from the buyer’s conveyancer demanding it;
• estate agent communications showing the transaction was otherwise progressing;
• the signed contract, transfer and completion statement confirming the actual completion date;
• the SDLT return and payment details for the later purchase.

If the evidence clearly shows that the delay arose because the parties were waiting for a document that did not exist, that may help establish both exceptional circumstances and causation. If the evidence is vague, or only shows general delay without identifying the reason, the claim becomes weaker.

It is also important not to confuse this type of argument with a separate claim that a property was uninhabitable or unsuitable for use. If a taxpayer is considering that route instead, the courts now apply a demanding test, especially after Mudan.

Outcome

A buyer in this position may have a viable SDLT refund claim if they can show that:

• they paid the higher rates when buying the new home;
• they later sold their previous main residence;
• the sale took place late because of exceptional circumstances beyond their control; and
• the misunderstanding over the supposed listed building completion document directly caused the delay.

On these facts, the claim is not automatic, but it is capable of being argued. The quality of the documentary evidence is likely to determine whether HMRC accepts the claim.

Practical Steps

If you are assessing a similar case, gather and review the following:

• the SDLT5 certificate or SDLT filing confirmation for the purchase of the new home;
• the sale contract, transfer deed and completion statement for the previous home;
• all conveyancer correspondence mentioning the document said to be required;
• estate agent messages showing the transaction timetable;
• a short chronology identifying when the issue first arose and how it affected exchange or completion.

Then ask these questions:

1. What was the normal deadline for the sale of the old home?
2. How far outside that deadline did completion occur?
3. What exactly caused the delay?
4. Was that cause outside the buyer’s control?
5. Can the documents prove the link between the issue and the delayed completion date?

If the answer to the last two questions is yes, there may be a proper basis for an exceptional circumstances claim.

Conclusion

Where a previous main residence is sold late because a conveyancing transaction was wrongly held up over a document that was thought to be required, an SDLT refund claim may be possible under the exceptional circumstances rules. The key is not simply showing that there was a delay, but proving exactly what caused it and why it was outside the buyer’s control.

Legal References Used

• Finance Act 2003, Schedule 4ZA
• 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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