# property.stamp-duty
Status: needs review by a conveyancing/tax professional before it is published.
The tax on buying land or property in the UK, which is three different taxes:
| region | tax | administered by |
|---|---|---|
| `england-ni` | Stamp Duty Land Tax (SDLT) | HMRC |
| `scotland` | Land and Buildings Transaction Tax (LBTT) | Revenue Scotland |
| `wales` | Land Transaction Tax (LTT) | Welsh Revenue Authority |
All three are "slice" taxes: the price is cut into bands and each band is
taxed at its own rate. `stampDuty` takes one purchase and returns the bands
it reaches, the tax on each, the total, and which schedule of rates applied.
## What it covers
- **Residential and non-residential** (non-residential includes mixed use)
purchase prices, for every region.
- **First-time buyers.** England: relief rates up to a price limit; above
the limit the relief is lost entirely and the standard rates apply to the
whole price (£500,000 → £10,000; £500,000.01 → £15,000). Scotland: the nil
band rises to £175,000, with no price limit. Wales has no first-time buyer
relief, so the main rates apply. From 8 July 2020 to 30 June 2021 England's
first-time buyer rates were replaced by the reduced standard rates, so the
standard schedule applies then.
- **Additional dwellings** (`additionalProperty`): England's higher rates
add 3 points to every band (5 points from 31 October 2024); Scotland's
Additional Dwelling Supplement is a separate charge on the whole price
(4%, then 6% from 16 December 2022, 8% from 5 December 2024); Wales's
higher residential rates are a separate table with their own bands. None
applies below £40,000.
- **Non-resident surcharge** (`nonResident`): England and Northern Ireland
only, 2 points on every residential band from 1 April 2021, on top of any
other rates including the nil band and first-time buyer rates. It does not
apply to non-residential purchases, and Scotland and Wales have none, so
the flag changes nothing there.
The caller says whether the higher rates apply. Whether a purchase attracts
them (replacing a main residence, spouses, inherited shares, the 36-month
refund window) is a legal judgement, not arithmetic.
## Rounding
Each tax is rounded down to the whole pound, once, from the exact sum of the
bands (HMRC SDLT Manual SDLTM00050: "The amount calculated is round down to
the nearest pound"; Revenue Scotland and the Welsh Revenue Authority return
guidance: tax entered rounded down to the nearest pound). In Scotland LBTT
and ADS are separate lines on the return, each rounded down on its own, so
they are here too: `bandTax` and `supplement`, with `total` their sum. The
per-band `tax` in `slices` is rounded down to the penny and is for display;
it is not what the total is built from.
## Rules as dated data
Every band, relief schedule and surcharge is a dated row in
`data/bands.json` and `data/surcharges.json`, taken from the date the
rates changed, and the lookup uses `effectiveDate` (normally completion).
The data covers every date from 1 April 2021 onwards in every region (and
back to 8 July 2020 in England, 27 July 2020 in Wales, 2016 and 2018 for
non-residential):
- England residential: 8 July 2020 (nil band £500,000), 1 July 2021
(£250,000), 1 October 2021 (£125,000 and a 2% band), 23 September 2022
(£250,000; first-time buyers £425,000 up to £625,000), 1 April 2025
(back to £125,000; first-time buyers £300,000 up to £500,000).
- Scotland residential from 1 April 2021 (unchanged through 2026-27).
- Wales main rates: 27 July 2020, 1 July 2021, 10 October 2022; higher rates
1 April 2018, 22 December 2020, 11 December 2024.
A date outside the data is an error, not a guess. A project installed with
`history=current` keeps only the rules still in force and refuses an older
date with an explanation rather than answering it with today's rates.
## What it does not do
- **Transitional contract rules.** Where a contract exchanged before a
change completes after it (England's 3% higher rates for contracts before
31 October 2024; Scotland's 6% ADS for contracts on or before 4 December
2024; Wales's October 2022 and December 2024 rules), the old rates may
apply. Pass the date whose rates apply as `effectiveDate`.
- Leases (SDLT/LBTT/LTT on the net present value of rent), linked
transactions, companies (England's 17% rate for non-natural persons over
£500,000), multiple dwellings relief (abolished in England from 1 June
2024), mixed-use apportionment, and other reliefs and exemptions.
- ADS on joint purchases or partial interests, and ADS or higher rates
repayment claims.
## Sources
England and Northern Ireland (SDLT), fetched September 2026:
- GOV.UK, "Stamp Duty Land Tax: Residential property rates" (current rates,
first-time buyers, 5% additional property surcharge, 2% non-resident
surcharge): https://www.gov.uk/stamp-duty-land-tax/residential-property-rates
- GOV.UK, "Stamp Duty Land Tax rates from 1 December 2003 to 31 March 2025",
and the period pages linked from it (8 July 2020 to 30 June 2021; 1 July
2021 to 30 September 2021; 1 October 2021 to 22 September 2022;
23 September 2022 to 30 October 2024; 31 October 2024 to 31 March 2025;
4 December 2014 to 7 July 2020 for the non-residential rates from
17 March 2016 and the 3% higher rates from 1 April 2016):
https://www.gov.uk/government/publications/rates-and-allowances-stamp-duty-land-tax
- GOV.UK, "Higher rates of Stamp Duty Land Tax" (not below £40,000):
https://www.gov.uk/guidance/stamp-duty-land-tax-buying-an-additional-residential-property
- GOV.UK, "Rates of Stamp Duty Land Tax for non-UK residents" (£40,000;
applies on top of the zero and first-time buyer rates; the £700,000
worked example, £39,000):
https://www.gov.uk/guidance/rates-of-stamp-duty-land-tax-for-non-uk-residents
- HMRC Stamp Duty Land Tax Manual SDLTM00050 (rounding):
https://www.gov.uk/hmrc-internal-manuals/stamp-duty-land-tax-manual/sdltm00050
Scotland (LBTT):
- Revenue Scotland, "Residential property" (rates from 1 April 2021,
first-time buyer nil band £175,000):
https://revenue.scot/taxes/land-buildings-transaction-tax/residential-property
- Revenue Scotland, "Non-residential property" (rates from 25 January 2019):
https://revenue.scot/taxes/land-buildings-transaction-tax/non-residential-property
- Revenue Scotland, "The Additional Dwelling Supplement (ADS)" (4% from
25 January 2019, 6% from 16 December 2022, 8% from 5 December 2024; on the
total price; not below £40,000):
https://revenue.scot/taxes/land-buildings-transaction-tax/additional-dwelling-supplement-ads
- Revenue Scotland, "About the calculation" (LBTT and ADS each rounded down
to the nearest pound):
https://revenue.scot/land-buildings-transaction-tax/guidance/how-to/paper-lbtt-return/about-calculation
- Scottish Government, "Scottish Budget 2026 to 2027: Scottish tax ready
reckoners" (LBTT rates and bands, including ADS, unchanged for 2026-27):
https://www.gov.scot/publications/scottish-budget-2026-2027-scottish-tax-ready-reckoners/pages/4/
Wales (LTT):
- Welsh Government, "Land Transaction Tax rates and bands" (main residential
rates from 27 July 2020, 1 July 2021 and 10 October 2022; higher
residential rates from 1 April 2018, 22 December 2020 and 11 December
2024; non-residential rates from 1 April 2018 and 22 December 2020):
https://www.gov.wales/land-transaction-tax-rates-and-bands
- Welsh Government, "Higher rates of Land Transaction Tax: overview" (a
residential property worth £40,000 or more):
https://www.gov.wales/higher-rates-land-transaction-tax-overview
- Welsh Government, "Land Transaction Tax return guidance: about the
calculation" (amounts rounded down to the nearest pound):
https://www.gov.wales/land-transaction-tax-return-guidance-about-calculation-all-transactions-html
1.0.1 fixes Python accepting a trailing newline or non-ASCII digits in effectiveDate; adds tests.