Tax Year

All income, deductions and taxes are measured over a defined period, so it is clear which year each item belongs to. That period is the tax year, also called the fiscal year for tax purposes in some countries.

Tax years differ by country. Some run from 1 January to 31 December. Others follow different dates: for example, the United Kingdom's individual tax year runs from 6 April to 5 April, Australia's from 1 July to 30 June and India's from 1 April to 31 March.

The tax year matters for planning. Income received or expenses paid just before or after the year-end can fall into different tax years, which may change how much tax is due in each. Allowances that reset each year, such as annual limits on tax-free savings, must often be used before the year ends or they are lost.

For example, someone wanting to use an annual tax-free savings allowance would need to make their contribution before the tax year ends.

Companies may have their own tax years aligned with their accounting periods.