How UK tax rates and thresholds changed across tax years, oldest first, with every superseded rule preserved under its effective dates.
Primary source: Income Tax rates and allowances: current and past (GOV.UK).
The Tax Rulebook preserves every rule under the effective dates it applied to, so a superseded rate stays visible rather than being overwritten. The tax history page reads that record oldest first, showing how rates and thresholds changed across the tax years the reference covers.