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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Deadline for Claiming
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.