How We Calculate
Every result on Tax Worked Out is worked out from the official rates published by HMRC, Revenue Scotland and the Welsh Revenue Authority. This page shows exactly how, and where each number comes from.
The slice method
Stamp duty, LBTT and LTT are charged in bands. Each rate applies only to the part of the price that falls inside its band, and the tax on each slice is added up. Scotland's Additional Dwelling Supplement is different: it is a flat percentage of the whole price, added on top.
Example: for a £500,000 home in England, a home mover pays £15,000: £125,000 at 0% = £0; £125,000 at 2% = £2,500; £250,000 at 5% = £12,500.
Rounding
We use the price in whole pounds. Then:
- Stamp Duty Land Tax is rounded down to the nearest pound. (GOV.UK)
- Land and Buildings Transaction Tax is kept to the penny. (Revenue Scotland)
- Land Transaction Tax is kept to the penny. (Welsh Revenue Authority)
Our official sources
Every rate, band, threshold and relief comes from these pages. All were last checked on 30 October 2026.
| Value | Applies from | Source and check |
|---|---|---|
| Residential ratesStamp Duty Land Tax (England and Northern Ireland) | 1 April 2025 | GOV.UKChecked 30 October 2026 |
| First-time buyer reliefStamp Duty Land Tax (England and Northern Ireland) | 1 April 2025 | GOV.UKChecked 30 October 2026 |
| Higher rates for additional homesStamp Duty Land Tax (England and Northern Ireland) | 1 April 2025 | GOV.UKChecked 30 October 2026 |
| Non-UK resident surchargeStamp Duty Land Tax (England and Northern Ireland) | 1 April 2021 | GOV.UKChecked 30 October 2026 |
| Non-residential ratesStamp Duty Land Tax (England and Northern Ireland) | Not stated | GOV.UKChecked 30 October 2026 |
| RoundingStamp Duty Land Tax (England and Northern Ireland) | Not stated | GOV.UKChecked 30 October 2026 |
| Residential ratesLand and Buildings Transaction Tax (Scotland) | 1 April 2021 | Revenue ScotlandChecked 30 October 2026 |
| First-time buyer reliefLand and Buildings Transaction Tax (Scotland) | 1 April 2021 | Revenue ScotlandChecked 30 October 2026 |
| Additional Dwelling SupplementLand and Buildings Transaction Tax (Scotland) | 5 December 2024 | Revenue ScotlandChecked 30 October 2026 |
| Non-residential ratesLand and Buildings Transaction Tax (Scotland) | 25 January 2019 | Revenue ScotlandChecked 30 October 2026 |
| RoundingLand and Buildings Transaction Tax (Scotland) | Not stated | Revenue ScotlandChecked 30 October 2026 |
| Main residential ratesLand Transaction Tax (Wales) | 10 October 2022 | Welsh Revenue AuthorityChecked 30 October 2026 |
| Higher residential ratesLand Transaction Tax (Wales) | 11 December 2024 | Welsh Revenue AuthorityChecked 30 October 2026 |
| Minimum price for higher ratesLand Transaction Tax (Wales) | Not stated | Welsh Revenue AuthorityChecked 30 October 2026 |
| Non-residential ratesLand Transaction Tax (Wales) | 22 December 2020 | Welsh Revenue AuthorityChecked 30 October 2026 |
| RoundingLand Transaction Tax (Wales) | Not stated | Welsh Revenue AuthorityChecked 30 October 2026 |
"Not stated" means the official page does not give a start date, so we do not guess one.
How we keep the rates up to date
- All rates live in one data file per tax, so a value can never differ between pages.
- We re-check every rate against the official pages the same week as any UK, Scottish or Welsh Budget, and update the "checked" date.
- Automated tests run the official worked examples from HMRC, Revenue Scotland and the Welsh Revenue Authority, plus the edge of every band. We run them before every change, and a change is not published if any test fails.
- Spotted an error? Email us and we will check it against the official source.
What we do not calculate
These cases follow special rules, so we link to the official guidance instead of guessing:
- A company buying a home: England and NI, Scotland, Wales
- Buying more than one home in one purchase: England and NI, Scotland, Wales
- Shared ownership: England and NI, Scotland, Wales
- Linked purchases from the same seller: England and NI, Scotland, Wales
- A new lease with rent: England and NI, Scotland, Wales
This is an estimate based on the official rates. Your solicitor or conveyancer will confirm the exact amount.