How we calculate
Where every rate on this site comes from, when it was last checked, and what the calculators deliberately leave out.
Rates are data, not opinion
Every threshold used on this site is held in a single file with a link to the official source and the date it was last checked against that source. No calculator contains a hard-coded figure, so a change at a Budget is a single edit rather than a hunt through the code.
The build refuses to run if any rate was last checked before the current tax year started, which means a stale figure stops a deployment instead of quietly reaching a visitor.
Sources and check dates
| Rate | Source | Last checked |
|---|---|---|
| Stamp Duty Land Tax, England and Northern Ireland | Official source | 1 August 2026 |
| Land and Buildings Transaction Tax, Scotland | Official source | 1 August 2026 |
| Land Transaction Tax, Wales | Official source | 1 August 2026 |
| Bank of England base rate | Official source | 12 September 2026 |
| Student maintenance loan, England | Official source | 12 September 2026 |
| Student maintenance support, Wales | Official source | 12 September 2026 |
| Student funding, Scotland (SAAS) | Official source | 12 September 2026 |
| Student maintenance, Northern Ireland | Official source | 12 September 2026 |
| Higher-rate refund rules, England and NI | Official source | 14 September 2026 |
| ADS repayment rules, Scotland | Official source | 14 September 2026 |
| Higher-rate refund rules, Wales | Official source | 14 September 2026 |
| Inflation indices (CPI, RPI) | Official source | 14 September 2026 |
| ISA and savings allowances | Official source | 1 August 2026 |
Three property taxes, not one
Property purchase tax is devolved. England and Northern Ireland charge Stamp Duty Land Tax, Scotland charges Land and Buildings Transaction Tax, and Wales charges Land Transaction Tax. Thresholds, first-time buyer relief and the treatment of additional properties all differ.
The difference most calculators miss: England, Northern Ireland and Scotland add a flat percentage of the whole price for additional properties, while Wales applies a separate rate table with its own thresholds. Treating Wales as a surcharge gives the wrong answer.
What these calculators are not
They are arithmetic. They do not recommend a product, compare named lenders, or account for your circumstances. Nothing here is financial advice, and no page carries a referral link to a lender or broker.
Spotted a figure that looks wrong? Tell us, with the numbers you entered, and it gets checked against the source.