This guide explains how Stamp Duty Land Tax (SDLT) should be thought about when assessing residential investment and development opportunities in England and Northern Ireland during the 2026 tax year. It is written for deal analysis, not as legal or tax advice.
Summary for 2026
SDLT is a transaction tax paid on completion. For a standard single residential purchase, the tax is calculated in bands. From 1 April 2025 the standard residential bands are:
| Purchase slice | Standard residential rate |
|---|---|
| Up to £125,000 | 0% |
| £125,001 to £250,000 | 2% |
| £250,001 to £925,000 | 5% |
| £925,001 to £1.5m | 10% |
| Above £1.5m | 12% |
Additional property surcharge
Most buy-to-let, second-home and company residential purchases are not standard single-property purchases. Where the higher rates for additional dwellings apply, add 5 percentage points to each residential band. That makes the 2026 higher-rate bands 5%, 7%, 10%, 15% and 17% respectively.
The higher rates can apply when the buyer will own another residential property worth £40,000 or more anywhere in the world at the end of the purchase day, subject to the detailed main-residence replacement rules and other exceptions.
Non-resident surcharge
A non-UK resident buyer of residential property in England or Northern Ireland may also face a 2 percentage point surcharge. This sits on top of the standard or higher-rate SDLT that already applies.
Developer and investor checks
- Residential, mixed-use or commercial. Mixed-use and non-residential assets can use a different SDLT rate table, so classify the property before relying on a residential calculation.
- Company purchase. Company acquisitions often trigger the higher residential rates, and high-value residential purchases can have specialist rules.
- Six or more dwellings. From 1 June 2024, buying six or more dwellings in one transaction is treated using the non-residential rates rather than the higher residential rates.
- Linked transactions. Multiple purchases between the same buyer and seller may need to be linked for SDLT.
- Reliefs and edge cases. First-time buyer relief, replacement of main residence and specialist reliefs should be checked before exchange.
How to apply this in Koreograph
Treat SDLT as part of the true entry cost. It affects cash in, ROI on cash, payback, refinance capital left in, and the offer price a deal can support.
- Model investor purchases using the higher-rate bands unless you have a clear reason not to.
- For mixed-use, commercial or six-plus-dwelling transactions, create a separate scenario and adjust SDLT manually if needed.
- Do not compare deals only on asking price. Compare them after SDLT, fees, refurb and finance costs.
- Use SDLT sensitivity where the deal is close to an offer threshold or where ownership structure is undecided.
Important caveat
SDLT is fact-specific. Use Koreograph to structure the decision, then confirm the treatment with a conveyancer or tax adviser before committing capital.