SDLT Refund Calculator
Calculate if you can reclaim Stamp Duty Land Tax. Check second home surcharge refunds, mixed-use classification, granny annexe exemptions, and overpayment relief — updated for 2026.
Last updated: March 2026
SDLT Refund Checker & Calculator 2026
Check all common overpayment scenarios and estimate your potential SDLT refund
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SDLT Rates at a Glance — Residential Property (England & Northern Ireland)
Standard Residential SDLT Rates (from 1 April 2025)
| Purchase Price Band | Standard Rate | Additional Dwelling (+5%) | First-Time Buyer |
|---|---|---|---|
| Up to £125,000 | 0% | 5% | 0% (up to £500k total) |
| £125,001 – £250,000 | 2% | 7% | 0% (up to £500k total) |
| £250,001 – £925,000 | 5% | 10% | 5% |
| £925,001 – £1,500,000 | 10% | 15% | 10% |
| Over £1,500,000 | 12% | 17% | 12% |
Non-Residential / Mixed-Use SDLT Rates
| Purchase Price Band | Non-Residential Rate |
|---|---|
| Up to £150,000 | 0% |
| £150,001 – £250,000 | 2% |
| Over £250,000 | 5% |
7 SDLT Refund Scenarios Every Property Owner Should Know
1. Higher Rates Surcharge Refund — Selling Your Old Home Within 3 Years
The additional dwelling surcharge (3% before October 2024, then 5%) is charged when you buy a new home without having sold your previous main residence. However, if you sell your old main residence within 3 years of purchasing the new property, you are entitled to a full refund of the surcharge. Example: bought new home for £450,000 in June 2023 — paid 3% surcharge = £13,500. Sold old home in October 2025 (within 3 years). Refund claim: £13,500 surcharge back from HMRC. Deadline: within 12 months of the sale of the old property OR within 12 months of the filing date of the original SDLT return — whichever is later. For most people, this means 12 months after the sale of the former home. Submit the claim by amending the original SDLT return or writing to HMRC.
2. Mixed-Use Misclassification — Non-Residential SDLT Rates Are Often Lower
If your property included a non-residential element (commercial unit, agricultural land over the curtilage, paddock, woodland, or a building with mixed use), it should have been assessed at non-residential SDLT rates. Non-residential rates are significantly lower on properties over £250,000: standard residential 5% on the slice from £250k–£925k vs. non-residential 5% on all amounts over £250k (no 10% or 12% bands). Example: a £650,000 farmhouse with agricultural outbuildings. Residential SDLT: £22,500. Non-residential SDLT: £20,000 (2% on £100k + 5% on £400k). Refund: £2,500. On larger properties, the savings can be tens of thousands. This area has seen considerable HMRC scrutiny and litigation — the classification depends on the specific facts of each case. Always get professional advice.
3. Granny Annexe and Subsidiary Dwelling Exemption
The subsidiary dwelling exemption prevents the higher rates surcharge applying to an entire property if it contains a secondary dwelling (granny flat, annexe, converted outbuilding) — provided the subsidiary dwelling's value is no more than one-third (33.3%) of the total purchase price. If this condition is met, the whole transaction is treated as a single main residential purchase without the surcharge. Example: £500,000 house with attached annexe (value £120,000 = 24% of total). The annexe qualifies as subsidiary — no higher rates surcharge applies. SDLT is charged at standard residential rates on the full £500,000. If the annexe was worth more than £167,000 (33.3% of £500,000), the exemption would not apply. Many buyers were incorrectly charged the surcharge on properties with granny flats — a refund claim may be available.
4. SDLT Refund Deadlines — Amendment vs Overpayment Relief
Understanding the correct deadline is critical — missing it means losing your refund. There are two routes: Amendment (12-month window): You can amend your SDLT return within 12 months of the filing date. The SDLT return must be filed within 14 days of completion. So the amendment window runs from the filing date for approximately 12 months from completion. This is the quickest and most straightforward route. Overpayment Relief (4-year window): Where the amendment window has expired, you can still claim overpayment relief for up to 4 years from the day after the effective date of the transaction. Overpayment relief requires a written claim to HMRC Stamp Taxes explaining the basis for the overpayment (error in law or fact). Both routes can result in a cash repayment with HMRC interest at 0.5% per annum on the overpayment (though this is relatively modest). Act quickly — every day closer to the deadline is a risk.
5. Uninhabitable Properties and SDLT
HMRC's guidance recognises that a property that is wholly unsuitable for use as a dwelling at the time of purchase may attract lower SDLT — or no residential SDLT at all. An uninhabitable property is one where: the property has no functioning kitchen or bathroom facilities, the structure is so dilapidated that it cannot be safely occupied, or planning permission requires a change of use before it can be used residentially. If the property was uninhabitable, it may be classed as non-residential for SDLT purposes, attracting lower non-residential rates. However, HMRC has consistently challenged uninhabitable property claims and the bar is very high — a property that merely needs renovation does not qualify. Specialist tax counsel's opinion is essential before making such a claim. Recent First-tier Tribunal cases have both upheld and rejected such claims depending on the specific condition of the property at the date of purchase.
6. Multiple Dwellings Relief — Abolished June 2024, Historic Claims Still Possible
Multiple Dwellings Relief (MDR) was abolished for transactions completing on or after 1 June 2024. However, for transactions completing before 1 June 2024 where MDR was not claimed, retrospective claims remain possible within the 12-month amendment window or 4-year overpayment relief window. MDR applied where two or more dwellings were purchased in a single transaction — the SDLT was calculated on the average price per dwelling (subject to a minimum 1% rate per dwelling). Common scenarios where MDR was available: purchasing a main house together with a separate self-contained annexe or cottage in the grounds on the same title; portfolio purchases of multiple flats. Example: two cottages purchased together for £600,000 (£300,000 each). Without MDR: SDLT on £600,000 = £20,000. With MDR: SDLT on £300,000 × 2 = £10,000 × 2 = £20,000 (in this case same — but on properties with different value splits the savings could be significant).
7. HMRC Refund Process and Professional Reclaim Services
HMRC typically processes SDLT refund claims within 6–8 weeks of receipt. You can submit a refund claim yourself — there is no legal requirement to use a third-party reclaim service. However, the market for SDLT refund claims is crowded with companies charging contingency fees of 25–40% of the refund amount. Before engaging such a company: assess the claim yourself using this calculator and published HMRC guidance. Consider a fixed-fee solicitor for straightforward surcharge refunds (typically £150–£350). Use a specialist tax counsel for complex mixed-use or uninhabitable property claims (higher cost but avoids aggressive claims HMRC will reject). Be aware of HMRC Spotlights warning against dubious "mixed-use" and "uninhabitable" claims that overstate the non-residential element to maximise refunds — these attract HMRC enquiries and can result in penalties of up to 100% of the underpaid tax.
Worked Examples: SDLT Refunds 2026
Example 1: Higher Rates Surcharge Refund on £450,000 Property
- Purchase: £450,000 in March 2023 — additional home (old home not yet sold)
- SDLT paid: Standard rates £10,000 + 3% surcharge on £450,000 = £13,500 = Total £23,500
- Old home sold: November 2024 (within 3 years)
- Surcharge refund: £13,500
- Deadline: 12 months from November 2024 sale = November 2025
- Process: Amend original SDLT return via HMRC portal
Example 2: Mixed-Use Property — Farmhouse with Agricultural Land
- Purchase: Farmhouse with 3 acres agricultural land for £750,000 in 2022
- SDLT paid at residential rates (incorrectly): £27,500
- Correct SDLT at mixed-use rates: 0% × £150k + 2% × £100k + 5% × £500k = £0 + £2,000 + £25,000 = £27,000
- Refund available: £27,500 − £27,000 = £500 (modest in this case)
- If property had been £1.2m: residential £63,750 vs. non-res £47,500 = refund of £16,250
- Note: Mixed-use classification requires the non-residential element to genuinely exist and be demonstrable
Example 3: Granny Annexe — Surcharge Should Not Have Applied
- Purchase: Main house with self-contained granny flat for £600,000 in 2024
- Annexe value: £130,000 (21.7% of £600,000 — below the 33.3% threshold)
- SDLT incorrectly charged: Standard £20,000 + 3% surcharge £18,000 = £38,000
- SDLT correctly charged (no surcharge as annexe ≤ 33.3%): £20,000
- Refund claim: £18,000
- Note: Only one transaction — buyer was purchasing as a main home replacement, not an additional home
How to Claim Your SDLT Refund — Step by Step
- Identify the overpayment scenario using the checker above. Common grounds: higher rates surcharge (sold old home within 3 years), mixed-use classification, granny annexe exemption, or uninhabitable property.
- Gather evidence: Original SDLT1 return confirmation, completion statement showing SDLT paid, and supporting evidence for your claim (sale of old home completion statement, surveyor's valuation splitting residential and non-residential elements, annexe planning documentation).
- Check the deadline: Are you within 12 months of the original SDLT return filing date? Use the amendment route. Beyond 12 months but within 4 years of the transaction? Use the overpayment relief route.
- For the 3-year surcharge refund: Log into HMRC's SDLT portal and amend the return, or write to HMRC Stamp Taxes, Birmingham (BX9 2EL). Include the UTRN (Unique Transaction Reference Number) from the original return, evidence of old property sale, and the calculation of the refund due.
- For overpayment relief: Write to HMRC Stamp Taxes setting out the grounds for the overpayment relief claim. Include the UTRN, the original SDLT1 details, the amount of overpayment claimed, and the legal basis (mistake of law or fact under Schedule 11A FA 2003).
- HMRC will respond within 6–8 weeks for straightforward claims. Complex claims (mixed-use, uninhabitable) may be subject to HMRC enquiry and take several months. Interest runs at the HMRC repayment rate from the date of overpayment.
Sources & Methodology
- HMRC – SDLT Reliefs Guidance
- HMRC – Higher Rates for Additional Dwellings
- HMRC – Mixed-Use Properties SDLT
- HMRC – Residential SDLT Rates
Disclaimer: This calculator provides a preliminary assessment only. SDLT refund eligibility is highly fact-specific. Submitting an incorrect SDLT claim can attract HMRC penalties. Always obtain professional advice from a qualified solicitor or tax adviser before making a claim.
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Frequently Asked Questions — SDLT Refunds
Official Sources & References
Data verified against official UK government sources. Last checked April 2026.