Can you get a stamp duty refund if your solicitor’s SDLT estimate was much lower than the final amount?

Introduction

People often search for this issue when the stamp duty land tax (SDLT) figure mentioned early in a purchase turns out to be far lower than the amount paid on completion. The key question is usually whether the extra SDLT can be reclaimed from HMRC, or whether the problem is really one of incorrect advice or poor handling by the conveyancer.

The answer depends on why the SDLT increased. A refund from HMRC is only available if too much SDLT was actually paid under the law. If the final amount was legally correct, HMRC will not refund it simply because an earlier estimate was wrong. In that situation, the issue may instead be whether the buyer was given negligent advice or an inaccurate quotation.

The Question

A buyer was initially given an SDLT figure of about £8,750 by their solicitors, but around £30,000 was then charged on completion. The buyer wants to know whether there may be grounds for a refund from HMRC, or whether they may need to consider a professional negligence claim against the solicitors instead.

Nick’s Explanation

Nick’s reasoning can be put simply: the first step is to identify why the SDLT figure changed. An early quote is often only an estimate based on limited facts. The final SDLT calculation may increase if, for example, the buyer already owned another dwelling, a relief was unavailable, the purchase price changed, mixed-use treatment did not apply, or the property did not qualify as uninhabitable.

In substance, Nick’s explanation is that there are really two separate questions:

• Was the SDLT actually overpaid as a matter of law?
• If not, was the buyer misadvised or inadequately informed before completion?

If the SDLT was correctly calculated under the legislation, HMRC is unlikely to give a refund. If the buyer was quoted too low a figure because the solicitor failed to identify the correct SDLT treatment, then the buyer may need to look at the conveyancing file, the retainer, the SDLT return and the completion statement to see whether there is a negligence issue.

Nick would also be likely to stress that buyers should not assume there is an HMRC refund just because the number changed dramatically. The legal basis for the tax must be checked first.

The Law

SDLT on land transactions in England and Northern Ireland is charged under the Finance Act 2003. The amount payable depends on the chargeable consideration and the applicable rate structure.

The main legal points commonly relevant in a case like this are:

• whether the transaction involved residential property, non-residential property, or mixed-use property under Finance Act 2003;
• whether the higher rates for additional dwellings applied under Schedule 4ZA Finance Act 2003;
• whether any relief was available, such as multiple dwellings relief for older transactions where still relevant to the effective date, or another statutory relief;
• whether the property was genuinely unsuitable for use as a dwelling at the effective date of the transaction;
• whether the SDLT return contained an error that can be amended or corrected; and
• whether an overpayment relief claim or repayment claim is available within the statutory time limits.

Where a buyer argues that a property should not be taxed as residential because it was uninhabitable, the courts now apply a relatively high threshold. Following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799, the condition threshold is now relatively high. The fact that a property needs repair, modernisation, or substantial work does not by itself mean it was unsuitable for use as a dwelling for SDLT purposes.

HMRC will generally only repay SDLT where the tax paid exceeded the amount properly due under the legislation. HMRC does not compensate for bad estimates, poor communication, or professional mistakes if the final tax figure was legally correct.

Analysis

The practical analysis usually works in the following order.

1. Check what was bought and at what price

   The starting point is the contract, transfer and completion statement. SDLT is driven by the actual transaction facts, not by an informal estimate given at an early stage.

2. Check whether the higher rates applied

   A jump from a lower figure to a much higher figure often happens because the 3% higher rates for additional dwellings were applied. That can occur if, at completion, the buyer owned another dwelling and was not replacing their only or main residence within the statutory rules.

3. Check whether any relief was assumed but later denied

   Sometimes an initial quote assumes mixed-use treatment or another relief. If that assumption later proves wrong, the SDLT can rise sharply. The same can happen if a buyer thought the property was uninhabitable, but the facts did not meet the legal threshold.

4. Check whether the property was said to be uninhabitable

   If the large difference arose because someone initially thought the dwelling was not suitable for use, that argument now needs very careful review. After Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799, the threshold is relatively high. Serious disrepair alone may not be enough.

5. Check the SDLT return actually filed

   The SDLT1 return and any supporting calculation should show the basis on which the tax was paid. If the return mis-stated the facts or applied the wrong rates, there may be scope to amend or reclaim. If the return was correct, HMRC is unlikely to refund anything.

6. Separate tax liability from solicitor conduct

   Even if the solicitor’s original estimate was poor, that does not itself reduce the SDLT legally due. The buyer may have a complaint or negligence claim only if the adviser failed to exercise reasonable care, failed to warn about uncertainty, or failed to apply the correct SDLT rules.

So the central distinction is this: a refund from HMRC depends on tax law; a claim against the solicitor depends on professional standards and causation.

Outcome

A buyer is not entitled to an HMRC refund just because the SDLT estimate was much lower than the final figure. A refund is only possible if the SDLT paid was more than the amount properly due under the Finance Act 2003.

If the final SDLT figure of around £30,000 was legally correct, the buyer’s possible remedy is more likely to lie in a complaint to the conveyancer, a report to the Legal Ombudsman if appropriate, or a professional negligence claim, depending on the facts and evidence.

If, however, the final SDLT was calculated on the wrong basis, there may be grounds to amend the return or make a repayment claim to HMRC within the relevant time limits.

Practical Steps

To assess the position properly, a buyer should gather and review the following:

• the solicitor’s original SDLT quote or estimate;
• any email explaining assumptions behind that estimate;
• the memorandum of sale, contract and transfer;
• the completion statement;
• the SDLT return submitted to HMRC;
• the SDLT5 certificate;
• details of any other properties owned at completion;
• details of whether the purchase replaced a previous only or main residence;
• any evidence relied on for mixed-use treatment, reliefs, or uninhabitability;
• photographs, surveys, invoices and reports if the property condition is relevant.

The next step is to ask three direct questions:

1. What exact SDLT treatment was used in the final return?
2. Was that treatment legally correct?
3. If it was correct, why was the earlier estimate so different?

If the return appears wrong, the buyer should seek a technical SDLT review promptly because amendment and repayment deadlines matter. If the return appears correct, the buyer should consider whether the conveyancer failed to advise properly about the likely SDLT position before exchange or completion.

Conclusion

A large gap between an initial SDLT quote and the final amount does not automatically mean HMRC owes a refund. The real issue is whether the SDLT was overpaid under the law. If it was not, the buyer may need to examine whether the conveyancer gave negligent or misleading advice instead. In any case involving alleged uninhabitability, the courts now apply a relatively high threshold following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799.

Legal References Used

• Finance Act 2003
• Schedule 4ZA 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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