How this instrument works
Stamp Duty Land Tax is charged on residential property bought in England and Northern Ireland — Scotland runs its own Land and Buildings Transaction Tax, and Wales its own Land Transaction Tax, both with different bands. SDLT is not a flat percentage of the price; it is sliced into bands, and each band's rate applies only to the portion of the price that falls inside it, the same logic income tax uses on wages.
Until December 2014 SDLT worked the opposite way: a single rate applied to the whole price once it crossed into a band, so paying £1 more could tip a purchase into a higher band and add thousands to the bill in one step. The reform replaced that slab structure with the slice-by-slice version modeled here, which is why a price just over £250,000 now costs only a little more in tax than a price just under it, rather than jumping to a new rate on the full amount. Home movers, first-time buyers past any relief threshold, and the conveyancing solicitors who work out completion funds are the people who run this sum, usually within days of an offer being accepted.
This sheet models the standard residential bands only. It excludes first-time buyer's relief, which raises the zero-rate threshold for qualifying buyers under a price cap; the additional-dwelling surcharge charged on second homes and buy-to-let purchases; and the extra surcharge non-UK residents pay. It also does not apply in Scotland or Wales, and SDLT thresholds get reset periodically at the Budget, so check gov.uk for the live figures before relying on this for a transaction that is about to complete.
- Enter the agreed price into Purchase price, £ — the full price on the completion statement, not the mortgage amount alone.
- Read Band 1 subtotal (0%, to £250,000) — it holds at £0 whatever the price is, since that opening slice is never taxed.
- Compare Band 2 subtotal (5%, to £925,000) against Band 3 subtotal (10%, to £1,500,000) to see how much each price slice contributes.
- Read Stamp Duty Land Tax owed, £ for the total bill — the sum every band produces once each slice is taxed at its own rate.
Worked example — a £350,000 house purchase
Set Purchase price, £ to 350,000 — a typical price for a family home moving within England. The first £250,000 of that sits inside Band 1 subtotal (0%, to £250,000), which stays at £0 no matter how high the price climbs, so none of that opening slice is taxed.
The remaining £100,000 falls inside the 5% band, because £350,000 clears £250,000 but stays under the £925,000 ceiling. That slice alone produces Band 2 subtotal (5%, to £925,000) of £5,000, and since the price never reaches £925,000, Band 3 subtotal (10%, to £1,500,000) and the top 12% band both add nothing further. Stamp Duty Land Tax owed, £ comes to exactly £5,000 — a plain 1.43% of the purchase price overall, not the 5% headline rate, because only the top £100,000 slice was ever charged at that rate.
Questions
Why is a £350,000 house not taxed at 5% of the full price?
Because SDLT taxes slices, not the whole price at one rate. The first £250,000 sits in the 0% band and pays nothing; only the £100,000 above that threshold is charged, at 5%, giving £5,000 total — an overall rate of 1.43% of the purchase price, well below the 5% headline figure for that band.
Does this calculator apply if I'm buying in Scotland or Wales?
No. Scotland charges Land and Buildings Transaction Tax and Wales charges Land Transaction Tax, each with its own bands and rates that differ from SDLT. This instrument models the England and Northern Ireland bands only — a purchase over the border needs the relevant national calculator instead.
Does this include first-time buyer's relief?
No. Qualifying first-time buyers get a higher zero-rate threshold and pay no SDLT up to that level, provided the property's price stays under the relief's price cap. This sheet applies the standard bands to every price entered, so a genuine first-time buyer's real bill may come in lower than the figure shown here.
Do I owe more Stamp Duty on a second home or buy-to-let?
In practice, yes — an additional-dwelling surcharge is added on top of the standard bands for second homes, buy-to-let purchases, and most purchases made by companies. This calculator applies only the standard residential bands, so someone buying an additional property should add the current surcharge percentage of the full price to the figure shown here.
Why did SDLT stop working as a single flat rate on the whole price?
Before December 2014 it did work that way — one rate applied to the entire price once it crossed into a band, so £1 extra could tip a purchase into a higher band and add thousands in one step. The reform replaced that slab structure with the sliced, band-by-band arithmetic this instrument runs, so the tax now rises smoothly with price instead of jumping at each threshold.
Will these exact bands still be current when I complete on a purchase?
Check gov.uk before relying on them for a live transaction. SDLT thresholds and rates are set by the Chancellor and have been revised more than once in recent years, so a purchase completing months from now could fall under different figures than the ones this sheet uses today.
References
- GOV.UK — Stamp Duty Land Tax: overview
- GOV.UK — Stamp Duty Land Tax rates for residential property
- GOV.UK — Pay Stamp Duty Land Tax
Read this first: This instrument shows arithmetic, not advice. Real offers add fees, taxes and terms that vary by lender and place — verify the figures against your actual paperwork before deciding anything.