How to Check Whether Your Conveyancer Overpaid Your Stamp Duty

A solicitor, agent or conveyancer "will usually file your return and pay the tax on your behalf on the day of completion", then add the tax to their fees (GOV.UK "Stamp Duty Land Tax", checked 28 October 2026). The return is still the buyer's, so if the conveyancing stamp duty figure was wrong, the buyer has to find and correct it, by amending the return within 12 months of the filing date or, after that, through an overpayment relief stamp duty land tax claim that closes 4 years after the effective date (HMRC SDLTM54000, checked 28 October 2026).

Did your conveyancer overpay your stamp duty? The paperwork from the purchase answers most of that question. Three checks cover the places an overpayment shows up on GOV.UK's own list of refund grounds: the arithmetic against the official bands, the classification of the property, and the reliefs and surcharges applied to it. Each check uses two documents the buyer already holds, the completion statement and the SDLT return.

Stamp Duty Land Tax applies to purchases in England and Northern Ireland. Scotland charges Land and Buildings Transaction Tax and Wales charges Land Transaction Tax (GOV.UK "Stamp Duty Land Tax", checked 28 October 2026).

How Stamp Duty Is Worked Out in a Conveyancing Transaction

Conveyancing stamp duty is charged on the "consideration", which is usually the price paid, and can include goods, works or services, the release of a debt or the transfer of a debt such as an outstanding mortgage (GOV.UK "Stamp Duty Land Tax", checked 28 October 2026). The tax is charged in slices: each rate applies only to the portion of the price inside its band, so a higher price never pushes the whole amount into a higher rate.

Which set of bands applies depends on how the property is used. GOV.UK gives two rate tables, one for residential property and one for non-residential or mixed property, and then adjusts the residential rates for first-time buyers, for buyers who will own more than one dwelling and for buyers who are not UK resident.

Residential portion of the price	Rate
Up to £125,000	0%
£125,001 to £250,000	2%
£250,001 to £925,000	5%
£925,001 to £1.5 million	10%
Above £1.5 million	12%

Source: GOV.UK "Stamp Duty Land Tax: Residential property rates", checked 28 October 2026. A buyer who will own another residential property after the purchase usually pays 5% on top of each of these rates, and a buyer who is not UK resident usually pays a further 2% surcharge on a residential purchase (same page).

Non-residential or mixed portion of the price	Rate
Up to £150,000	0%
£150,001 to £250,000	2%
Above £250,000	5%

Source: GOV.UK "Stamp Duty Land Tax: Rates for non-residential and mixed land and property", checked 28 October 2026.

Companies buying residential property have their own rules. GOV.UK's guidance for corporate bodies says SDLT is charged at 17% on residential property costing more than £500,000 bought by companies and by partnerships with a company as a partner, and that a 5% surcharge applies to residential property bought by companies (GOV.UK "Stamp Duty Land Tax: corporate bodies", checked 28 October 2026). Relief from the 17% rate is available in defined cases, and it has to be claimed.

Why Conveyancers Overpay, and Who Carries the Risk

The Finance Act 2003 gives the right to amend a return to "the purchaser", who "may amend a land transaction return given by him by notice to the Inland Revenue" (Finance Act 2003, Schedule 10, paragraph 6(1), legislation.gov.uk, checked 28 October 2026). The conveyancer prepares and sends the return, but the return and the tax on it belong to the buyer.

HMRC applies the same rule to refunds. GOV.UK's refunds page says a buyer who pays an agent to claim "is still responsible for checking whether your claim is correct" and must repay the refund in full, with any interest or penalties, if the agent's claim is wrong (GOV.UK "Refunds of Stamp Duty Land Tax", checked 28 October 2026). HMRC's compliance check guidance puts it more broadly: "even if you have an agent, you're personally responsible for your own tax affairs" (GOV.UK "Stamp Duty Land Tax: HM Revenue and Customs compliance checks", checked 28 October 2026).

The rate that applies depends on facts the conveyancer may not see on the contract: whether the buyer owns another dwelling anywhere, whether part of the building is a shop or office, whether the land beyond the house is part of its garden or grounds, and whether the buyer qualifies for a relief. HMRC's own calculator works out the tax "for most transactions" and tells users to check the guidance if they "believe it may qualify for a relief" (HMRC "Calculate Stamp Duty Land Tax", checked 28 October 2026). A return built on the calculator's default answers can be arithmetically correct and still charge the wrong rates.

What a buyer reads as conveyancer overcharging on the completion statement is usually a question about the tax line, which the firm passes to HMRC. Any refund of that tax comes from HMRC, and HMRC "will pay any refund to you unless you give permission to pay it to someone else" (GOV.UK "Apply for a refund of Stamp Duty Land Tax", checked 28 October 2026).

What Happens When a Conveyancer Gets the Figure Wrong

What happens if a conveyancer makes a mistake depends on which way the figure is wrong. If the return overstated the tax, the buyer can recover the difference through the two routes set out below, provided the claim is made in time. If the return understated it, the shortfall is still the buyer's: HMRC says the buyer "may have to pay interest if the tax should have been paid earlier, as well as a penalty", and it considers penalties where an inaccuracy is "because of careless or deliberate behaviour" (GOV.UK "Stamp Duty Land Tax: HM Revenue and Customs compliance checks", checked 28 October 2026). The same guidance asks anyone who thinks something is wrong on a return to tell HMRC "as soon as possible".

A mistake in the service, or conveyancer overcharging on the firm's own fees, is a matter between the buyer and the firm. The Legal Ombudsman says the first step is to complain to the service provider, which "has up to eight weeks to put things right", and that a complaint can come to the Ombudsman after that period or after an unsatisfactory response (Legal Ombudsman "How to complain", checked 28 October 2026). A complaint does not stop the HMRC time limits running, so the buyer should correct the return while the complaint is being dealt with.

GOV.UK's list of refund grounds shows where returns go wrong. It includes paying residential rates where non-residential rates applied, failing to claim a relief or exemption, a mistake in calculating the tax, paying more than the amount calculated, paying the higher rates on a new main home before selling the old one, and paying the non-resident surcharge before becoming UK resident (GOV.UK "Refunds of Stamp Duty Land Tax", checked 28 October 2026).

Can a Conveyancer Reclaim Overpaid SDLT?

Yes. A solicitor, agent or legal conveyancer can make the refund request for the buyer, and GOV.UK asks them to include "a letter of authority from all of the buyers on the SDLT return" (GOV.UK "Apply for a refund of Stamp Duty Land Tax", checked 28 October 2026). HMRC pays refunds only to the purchasers unless the purchasers sign a letter confirming who should be repaid, and the page warns that "a general form of authority may not be enough".

Agents can also use HMRC's online form to claim back the higher rates on a replaced main home, with a signed letter of consent from the main buyer (GOV.UK "Apply for a refund of the higher rates of Stamp Duty Land Tax", last updated 10 March 2025). Whoever makes the claim, the buyer remains responsible for checking it.

The Two Documents That Show What Was Filed

Answering "did your conveyancer overpay your stamp duty?" starts with two documents. The conveyancer completion statement is the money account for the purchase. It sets the price against the deposit and any mortgage advance, lists the firm's fees, and lists the disbursements the firm paid out for the buyer, with Stamp Duty Land Tax among them. The figure on the SDLT line is the amount the firm paid to HMRC, and it is the number every check below starts from. Read the fee lines separately: a complaint of conveyancer overcharging on fees goes to the firm, while an overpayment of tax goes to HMRC. Note the completion date on the statement as well, because the time limits run from it.

The SDLT return is what HMRC received. It records what was bought, the effective date (normally completion), the consideration, the type of property, any relief claimed and the tax calculated. Ask the conveyancer for a copy of the submitted return if it is not in the completion pack. For a return filed online, HMRC issues an SDLT5 certificate, which "proves you sent the return" and goes to HM Land Registry with the application to register the property (GOV.UK "Stamp Duty Land Tax online and paper returns", checked 28 October 2026).

The SDLT5 also carries the Unique Transaction Reference Number (UTRN). HMRC's guidance on amending a return says the UTRN is on the SDLT5 certificate for an online return, or on the return and the certificate for a paper one, and that any letter amending the return must quote it (GOV.UK "Tell HMRC about changes to your Stamp Duty Land Tax return", checked 28 October 2026). Some company purchases also need an SDLT4, which HMRC says is used "for complicated leases, commercial transactions and some residential situations" (GOV.UK "Stamp Duty Land Tax online and paper returns").

Before running the checks, gather:

• the completion statement, with the SDLT line and the completion date;
• the submitted SDLT return, and the SDLT4 if one was filed;
• the SDLT5 certificate with the UTRN;
• the contract and the transfer deed or lease;
• a plan or description of every part of the property, including any commercial space, outbuildings and land beyond the garden.

Check One: Re-Run the Arithmetic Against the Official Bands

How to check tax overpayment on the return starts with the arithmetic. GOV.UK's worked example for a £295,000 home bought by someone who will own no other residential property is:

• 0% on the first £125,000 = £0
• 2% on the next £125,000 = £2,500
• 5% on the final £45,000 = £2,250
• total SDLT = £4,750

Source: GOV.UK "Stamp Duty Land Tax: Residential property rates", checked 28 October 2026.

Work through the buyer's own price in the same way, using the table that matches the classification on the return, and compare the total with the conveyancing stamp duty line on the completion statement and the tax shown on the return. Then run the purchase through HMRC's SDLT calculator, which covers first-time buyers, replacement of a main residence, additional properties, residential and non-residential purchases, freehold and leasehold, and non-UK resident buyers (HMRC "Calculate Stamp Duty Land Tax", checked 28 October 2026).

A difference at this stage points to a calculation error or a payment error, both of which are on GOV.UK's list of refund grounds. The calculator also flags its own limit: "There are different rules for a corporate body purchasing residential property for more than £500,000", so a company buyer above that price needs the corporate bodies guidance rather than the calculator alone.

A matching figure shows only that the arithmetic is right for the answers given. If the return described the property or the buyer wrongly, the calculator will reproduce the same wrong figure. Checks Two and Three test those answers.

Check Two: Was the Property Classified Correctly?

The set of rates used on the return is the single largest variable in the figure. GOV.UK lists as non-residential: commercial property such as shops or offices; property "not suitable to be lived in" that cannot be made suitable, such as a building at high risk of structural collapse; forests; agricultural land that is part of a working farm or used for agricultural reasons; "any other land or property that is not part of a dwelling's garden or grounds"; and 6 or more residential properties bought in one transaction (GOV.UK "Stamp Duty Land Tax: Rates for non-residential and mixed land and property", checked 28 October 2026). A mixed property has both elements, "for example a flat connected to a shop, doctor's surgery or office", and is taxed on the non-residential table.

Applied to the £295,000 example, the non-residential table gives:

• 0% on the first £150,000 = £0
• 2% on the next £100,000 = £2,000
• 5% on the final £45,000 = £2,250
• total SDLT = £4,250

That is £500 less than the £4,750 residential figure. The gap stays at £500 up to £925,000, widens above that price where the residential rates rise to 10% and 12%, and grows by any surcharge charged on the residential calculation.

Mark on the plan every element that is not part of a dwelling or its garden and grounds, and compare it with the property type on the return. The test for whether a building with a shop, surgery or office counts as mixed use is set out in Can You Claim an SDLT Refund on a Mixed-Use Property? Land bought in a contaminated or derelict state matters here only for the rates; the corporation tax relief on cleaning it up is covered in Land Remediation Relief: Claiming for Contaminated or Derelict Sites.

Check Three: Reliefs and Surcharges That May Have Been Missed

The eligibility criteria for stamp duty reliefs sit in HMRC's guidance, and GOV.UK says the buyer "must complete an SDLT return to claim relief, even if no tax is due" (GOV.UK "Stamp Duty Land Tax: Reliefs and exemptions", checked 28 October 2026). A relief that was available but left off the return was not given. Test each of these against the purchase:

• First-time buyers. Where the buyer and everyone buying with them are first-time buyers, there is no SDLT up to £300,000 and 5% on the portion from £300,001 to £500,000; above £500,000 the relief cannot be claimed (GOV.UK "Residential property rates", checked 28 October 2026).
• The 5% higher rates. These apply where the purchase means the buyer will own more than one dwelling. They do not apply where the purchase replaces the buyer's main residence and the previous main residence was sold within 36 months of completing the new purchase (same page). If the old home was still unsold at completion, the higher rates were due on the day and a refund comes later.
• Company purchases. The 5% surcharge on residential property bought by companies, the 17% rate above £500,000 and the reliefs from that rate all turn on the buyer and the use of the property (GOV.UK "corporate bodies", checked 28 October 2026).
• Other reliefs. GOV.UK's list includes companies transferring property to another company, building companies buying an individual's home, employers buying an employee's house, charities and freeport tax sites.
• Several dwellings in one deal. GOV.UK says "you can no longer claim SDLT relief for multiple dwellings", so a recent purchase of several units needs the checks in SDLT on Buying Multiple Dwellings in One Transaction: What to Check, including whether 6 or more dwellings put the deal on the non-residential table.

On the £295,000 example, the higher rates add 5% to each band:

• 5% on the first £125,000 = £6,250
• 7% on the next £125,000 = £8,750
• 10% on the final £45,000 = £4,500
• total SDLT = £19,500

Against £4,750 at the standard rates, that is £14,750 of higher-rate tax. A buyer who paid it on a new main home can apply for it back after selling the previous main home within 3 years of buying the new one, and HMRC must receive the request by the later of 12 months after the sale and 12 months after the filing date of the return for the new home (GOV.UK "Apply for a refund of the higher rates of Stamp Duty Land Tax", last updated 10 March 2025).

Amendment or Overpayment Relief: The Two Routes Back

Once a check has found a wrong figure, the Finance Act 2003 gives two routes to recover it. The first is to amend the return. The purchaser gives notice to HMRC, and "an amendment may not be made more than twelve months after the filing date" (Finance Act 2003, Schedule 10, paragraph 6(3), legislation.gov.uk, checked 28 October 2026). Where the amendment would produce a repayment, the notice must be accompanied by the contract and the instrument, if any, by which the transaction was effected (paragraph 6(2A)). The letters, evidence and address for that route are set out in How to Reclaim Overpaid Stamp Duty Land Tax From HMRC.

The second route opens after the amendment window closes. From 1 April 2011 a person may claim overpayment relief to recover overpaid SDLT, and "the time limit for a claim to relief is four years after the effective date of the transaction" (HMRC SDLTM54000, checked 28 October 2026). An overpayment relief stamp duty land tax claim is made by letter, outside the return.

The two routes do not cover the same mistakes. HMRC's manual says overpayment relief "is not due" where the tax is excessive because of a mistake "in making any other claim or election, or failing to do so" (HMRC SDLTM54110, checked 28 October 2026). A relief left off the return should therefore be claimed by amendment inside the 12 months. HMRC "may in limited circumstances accept a late claim or election" (same page), but a buyer should not plan around that.

HMRC pays quickly: it "will usually make the payment directly into your bank account within 15 working days of receiving your claim" (GOV.UK "Refunds of Stamp Duty Land Tax", checked 28 October 2026), and it makes the payment "without checking eligibility", which means it can check the claim afterwards and ask for the money back (GOV.UK "Apply for a refund of Stamp Duty Land Tax").

When Can You Claim? The Time Limits That Decide

When can I claim overpayment relief, and when is it too late to amend? Both answers start from the effective date, which for most purchases is completion. HMRC's guidance says "the filing date is 14 days after the effective date of your transaction", and the 12 months for amending run from that filing date (GOV.UK "Tell HMRC about changes to your Stamp Duty Land Tax return", checked 28 October 2026).

Route	Window	Source
Amend the return	Up to 12 months after the filing date	FA 2003 Sch 10 para 6(3)
Overpayment relief	After the amendment window, up to 4 years after the effective date	HMRC SDLTM54000
Higher rates refund on a replaced main home	Later of 12 months after the sale and 12 months after the filing date	GOV.UK higher rates refund guidance

For a purchase that completed on 2 December 2025, the dates work out as follows:

• effective date (completion): 2 December 2025
• filing date, 14 days later: 16 December 2025
• last day to amend the return: 16 December 2026
• last day for an overpayment relief stamp duty land tax claim: 2 December 2029

A purchase completed late in 2025 is therefore still inside the amendment window at the end of October 2026, and that is the window in which a missed relief should be claimed. Purchases more than 4 years past their effective date are outside both routes, so work through the most recent purchase first and then each older one in date order.

Conclusion and the Company Eligibility Check

The question "did your conveyancer overpay your stamp duty?" comes down to four lines, worked through in order with the completion statement and the SDLT return beside them:

• Arithmetic: the price re-run through the right bands and HMRC's calculator matches the SDLT line.
• Classification: every commercial, agricultural, uninhabitable or non-garden element is reflected in the property type on the return.
• Reliefs and surcharges: each relief the buyer qualified for was claimed, and each surcharge charged was due.
• Dates: the filing date, the last day to amend and the 4-year limit are written beside the purchase.

A wrong stamp duty figure on one purchase is one form of overpayment; the wider signals across bills, filings and premises costs are covered in Signs Your Business Has Been Overpaying Without Knowing It. Run the business savings check to see which refunds and reliefs the company's property purchases and other costs may still support.