UK historic Multiple Dwellings Relief.
MDR SDLT (pre-June 2024)
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Standard SDLT now
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A relief that ended, and why it still matters
Multiple Dwellings Relief was a Stamp Duty Land Tax break for anyone buying two or more dwellings in a single transaction or a linked set of transactions. It was abolished from 1 June 2024. So why keep a calculator for it? Because completed purchases do not vanish from HMRC records, and a surprising number of buyers between 2016 and mid-2024 either overpaid or were entitled to claim and never did. SDLT can be amended within roughly 12 months of the filing date, and disputes over historic MDR claims still run through the tribunal. If you bought a property with an annexe, a block of flats, or a house plus a self-contained granny flat in that window, this page shows you what the relief would have produced and whether a review is worth a conversation with an SDLT specialist.
The averaging trick at the heart of MDR
The relief worked by averaging. Instead of charging SDLT on the whole purchase price as one lump, you divided the total by the number of dwellings, calculated the duty on that average price using the standard residential bands, then multiplied back up. Because SDLT is progressive, splitting a large price into several smaller ones dropped most of it into the cheaper 0% and 2% bands. A statutory floor of 1% of the full price always applied, so the relief could never take the bill below that line.
Three flats for £1.5 million
Take the default: a £1,500,000 purchase of three dwellings. The average price per dwelling is £500,000. Standard residential SDLT on £500,000 is £15,000 (nothing on the first £125,000, 2% on the next £125,000, then 5% on the £250,000 above that). Multiply by three dwellings and MDR gives £45,000. The 1% floor would only be £15,000, so it does not bite. Buying the same £1,500,000 as a single dwelling today, with no relief, costs £93,750. The averaging therefore saved £48,750.
| Step | Figure |
|---|---|
| Total price | £1,500,000 |
| Average per dwelling (÷ 3) | £500,000 |
| SDLT per dwelling | £15,000 |
| MDR bill (× 3) | £45,000 |
| Standard SDLT on £1.5m today | £93,750 |
| Saving the relief delivered | £48,750 |
The bar on the left is barely half the height of the bar on the right. That gap is exactly why MDR was attractive to portfolio landlords and developers, and exactly why the Treasury closed it.
One thing this model leaves out
The standard SDLT figure shown here uses the ordinary residential bands. It does not add the additional-dwelling surcharge that usually applies to second homes and buy-to-let, nor the non-residential rates that can apply when six or more dwellings are bought together. Treat the comparison as a clean like-for-like on the headline bands. Anyone with a live transaction should price the surcharge separately, because for an investor it often changes the answer more than the relief ever did.
What counted as a separate dwelling?
A dwelling had to be suitable for use as a single self-contained home, with its own kitchen, bathroom and separate access. A genuinely independent annexe could qualify. A spare room or a loft conversion did not. Many of the post-2024 disputes turn precisely on whether an annexe was self-contained enough on completion day.
Can I still claim on an older purchase?
Only within the amendment window, which is broadly 12 months from the SDLT filing deadline. Transactions that exchanged before 6 March 2024 could still complete and claim under transitional rules, but for anything outside the time limit the door is closed. Take advice before paying a no-win-no-fee firm to chase a historic refund, because HMRC has actively challenged weak annexe claims and a refund that is later overturned must be repaid, sometimes with interest and penalties on top. A genuine claim by a developer who bought a converted block of flats is one thing. A speculative claim on an ordinary family home with a studio over the garage is exactly the kind HMRC has been winning at tribunal.