Tax year
The 12-month period over which annual tax is computed — calendar year in most countries, April-to-April in the UK.
A tax year is the 12-month period that anchors the annual tax computation. Bands, allowances, and rates are pinned to a specific tax year — the same gross salary can produce different net pay in different tax years if the underlying rules change.
Country conventions on this site: UK runs 6 April to 5 April of the following year — 2025/26 covers 6 Apr 2025 → 5 Apr 2026. US, Germany, France, and Spain all run on the calendar year (1 January to 31 December). The site shows the active tax year in each calculator's footer and in every breakdown line.
Tax-year boundaries matter for two reasons: (1) any pay received between the boundaries falls under that year's rules, even if work was performed in the previous year; (2) bonuses, redundancy, and pension contributions can sometimes be deferred or accelerated across the boundary for tax planning. This calculator does not model deferrals — it shows the tax owed against a single specified tax year's rules.
Calculator pages that use this term
See also
- Gross pay — The total annual salary before any tax, social-insurance, or pension deductions are taken out.
- Net pay (take-home) — The amount actually deposited in the employee's bank account after every statutory deduction.
- Marginal tax rate — The percentage paid in tax on the next unit of income earned — distinct from the average effective rate.
- Effective tax rate — Total deductions divided by gross pay — the single percentage that summarises the overall tax bite.