Between May 2010 and July 2024, the Conservative Party governed the United Kingdom for fourteen years — first in coalition with the Liberal Democrats, then in single-party government, then through three further prime ministers. Over that period, Stamp Duty Land Tax went through more substantive change than in any comparable period since its 2003 introduction. Some changes were genuinely transformative; some were temporary fixes that aged badly; and one — the additional-dwelling surcharge — reshaped the landlord market in ways still being felt.
This article walks through the lot in date order. It is intended as a reference rather than a polemic — we've tried to describe each change on its own terms.
2010–2014: minor adjustments
The early Cameron years saw relatively little reform. A first-time buyer relief introduced under Labour was abolished in 2012; a 7% rate on properties above £2m was introduced in the 2012 Budget; and a 15% flat rate on residential properties purchased through corporate envelopes for over £2m was introduced alongside the Annual Tax on Enveloped Dwellings (ATED). These were targeted measures rather than systemic reform.
December 2014: slab to slice — the transformative reform
George Osborne's 4 December 2014 Autumn Statement replaced the long-standing "slab" SDLT system — under which a single rate applied to the entire purchase price once the threshold was crossed — with a progressive "slice" system. Under the old rules, paying £251,000 meant 3% on the whole price (£7,530), versus 1% (£2,500) at £250,000. The new system applied each rate only to the slice of price within its band, eliminating the cliff edges that had distorted the market for decades.
The reform was broadly welcomed across party lines and remains the largest structural change to SDLT in living memory. We cover the mechanics in detail in our slab vs slice deep dive.
April 2016: the additional-dwelling surcharge
Cameron and Osborne introduced a 3% SDLT surcharge on second residential property purchases — applying to any buyer who, on completion, owned another residential property anywhere in the world and was not replacing their only or main residence. The change was aimed at slowing the growth of the private rented sector and at reducing competition between landlords and first-time buyers. It raised significant revenue and made the entry economics of small-scale buy-to-let materially worse.
November 2017: first-time buyer relief
Philip Hammond's Autumn Budget reintroduced first-time buyer SDLT relief, this time at the £300,000 nil-rate and with a £500,000 cap. This pattern — FTB relief at £300k, capping at £500k — became the default and is what the system reverted to in April 2025 after the Truss-era boost lapsed.
July 2020 – September 2021: the Covid stamp duty holiday
Rishi Sunak's response to pandemic housing market paralysis was a temporary increase of the nil-rate threshold to £500,000, announced on 8 July 2020. The holiday was tapered: full £500,000 threshold to 30 June 2021, £250,000 threshold from 1 July to 30 September 2021, then back to £125,000. Transaction volumes spiked, prices rose roughly 10% year-on-year, and the policy is widely judged to have stimulated short-term activity while raising long-term prices.
April 2021: the non-resident surcharge
An additional 2% surcharge was introduced on residential property purchases in England and Northern Ireland by non-UK residents. The surcharge stacks on top of standard SDLT rates and the additional-dwelling surcharge where applicable.
September 2022: the Truss mini-budget
Kwasi Kwarteng's 23 September 2022 mini-budget raised the standard nil-rate threshold from £125,000 to £250,000, and the first-time buyer threshold from £300,000 to £425,000 (with relief capping at £625,000). Most of the rest of the mini-budget was reversed within weeks under Jeremy Hunt, but the SDLT change survived. It was sunsetted to expire on 31 March 2025 — a date that arrived under a Labour government that chose not to extend it.
The legacy
Stripping out the political noise, the substantive Conservative inheritances on SDLT are: (1) the slice system, which is here to stay; (2) the additional-dwelling surcharge, which Labour has raised but not removed; (3) the principle of an FTB relief with a cap; and (4) the non-resident surcharge. The threshold experiments — the holiday and the Truss boost — were both temporary and have been wound back.
A note on refunds
If you completed under any of the higher-threshold periods covered above, your SDLT was calculated on the rates in force at the date of completion — there's no retrospective relief. But many buyers still overpaid by not deducting chattels or by missing reliefs they were entitled to. See our refund estimator for a quick check.
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