Sources

Choosing sources

We prioritise legislation and publications from the public body responsible for a rule. Calculator pages link to the specific references used, alongside a tax year or effective period where relevant. Linking to an official source does not imply official approval.

Income, employment and dividends

• GOV.UK: Income Tax rates and allowances
• GOV.UK: National Insurance rates and categories
• GOV.UK: Tax on dividends
• GOV.UK: Self-employed National Insurance rates

VAT

• GOV.UK: VAT rates
• GOV.UK: Register for VAT
• GOV.UK: VAT thresholds

Using references

Official publications may cover exceptions outside a calculator’s scope. Read both the calculator’s assumptions and the original guidance. General arithmetic tools, such as gross salary conversions, use stated mathematical relationships rather than tax rates.

Changed or broken sources

Official pages may move or change. Please tell us about a broken link or changed rule. Read our Methodology for how we handle rate data and review dates.