Data sources
Full provenance of every dataset on SalaryTax: HMRC, ONS, gov.scot, gov.wales, and NHS Employers, with retrieval dates and update cadence. Licensed CC BY 4.0.
Every dataset that powers a SalaryTax calculator is documented here with its authoritative source, retrieval date, and the cadence at which we refresh it. Last reviewed: 2026-10-01.
For testing approach, regional coverage, and known limitations see our methodology.
Tax rules
| Data | Source | Retrieved | Update cadence |
|---|---|---|---|
| UK Income Tax bands (2023-24 through 2026-27; frozen to 2030-31) | gov.uk - Income Tax rates | 2026-10-01 | Annual (6 April) |
| Scottish Income Tax 2023-24 | gov.scot - Scottish Income Tax 2023-2024 | 2026-04-17 | Annual |
| Scottish Income Tax 2024-25 | gov.scot - Scottish Income Tax (policy page) | 2026-04-17 | Annual |
| Scottish Income Tax 2025-26 | gov.scot - Scottish Budget 2025-26 | 2026-04-17 | Annual |
| Scottish Income Tax 2026-27 | gov.scot - Scottish Income Tax rates and bands 2026-27 | 2026-04-18 | Annual |
| National Insurance Class 1 / 2 / 4 | gov.uk - National Insurance rates and categories | 2026-10-01 | Annual |
| Self-employed National Insurance rates | gov.uk - Self-employed NI | 2026-10-01 | Annual |
| Student loan thresholds (Plan 1, 2, 4, 5, PG) | gov.uk - Repaying your student loan: what you pay | 2026-10-01 | Annual (April) |
| High Income Child Benefit Charge | gov.uk - Child Benefit tax charge | 2026-10-01 | Annual |
| Marriage Allowance | gov.uk - Marriage Allowance | 2026-10-01 | Ad hoc |
| Dividend tax rates and allowance | gov.uk - Tax on dividends | 2026-10-01 | Annual |
| Personal Savings Allowance | gov.uk - Apply tax-free interest on savings | 2026-10-01 | Annual |
| Blind Person's Allowance | gov.uk - Blind Person's Allowance | 2026-10-01 | Annual |
| Welsh Rate of Income Tax (WRIT) | gov.wales - Welsh Rates of Income Tax | 2025-04-17 | Annual |
Economic data (ONS)
| Data | Source | Retrieved | Update cadence |
|---|---|---|---|
| CPI annual averages (series D7BT) | ONS - CPI D7BT | 2026-08-02 | Annual (January release) |
| UK median full-time salary | ONS - Annual Survey of Hours and Earnings 2025 | 2026-07-02 | Annual (October) |
| UK annual salary percentiles | ONS ASHE 2025 Table 1.7a (annual pay - gross) | 2026-07-02 | Annual |
| Regional median salaries (12 UK regions) | ONS - Annual Survey of Hours and Earnings 2025 bulletin | 2026-06-23 | Annual |
Role and job-band mapping
| Data | Source | Retrieved | Update cadence |
|---|---|---|---|
| NHS Agenda for Change pay scales | NHS Employers - Pay scales 2026/27 | 2026-10-01 | Annual |
| Teacher pay scales (England) | gov.uk - Teachers' pay scales and allowances | 2026-10-01 | Annual |
| Civil Service pay benchmarks | gov.uk - Civil Service pay remit guidance | 2026-10-01 | Annual |
| Occupation pay by 4-digit occupation code (SOC 2020 unit groups) | ONS Annual Survey of Hours and Earnings, Table 14.7a (2025 provisional) | 2026-08-04 | Annual |
Update process
- March - before the new tax year starts on 6 April:
add
src/data/tax/uk-YYYY-YY.tswith the published HMRC, gov.scot and gov.wales rates and bumpCURRENT_TAX_YEAR. Public-sector pay scales (NHS, teachers, civil service) are updated when each pay award is published. - January - after ONS publishes the December CPI figure: add the new calendar-year CPI annual average.
- October to January - after ONS publishes the annual ASHE release: update the median salary, salary percentiles and regional medians.
License
Site content (methodology narrative, calculator UX, presentation of derived data) is licensed under Creative Commons Attribution 4.0 International (CC BY 4.0). Underlying tax rules and economic statistics are public-sector information published by gov.uk, gov.scot, gov.wales, NHS Employers, and ONS - those retain their original licenses (predominantly the Open Government Licence v3.0). When reusing SalaryTax content, please attribute "SalaryTax (salarytax.uk)".