UK Tax Year: When Does It Start and End?

When Is the UK Tax Year?

The UK tax year runs from 6 April to 5 April the following year. For example, the 2026-27 tax year runs from 6 April 2026 to 5 April 2027.

Why 6 April?

This unusual date dates back to 1752, when Britain switched from the Julian calendar to the Gregorian calendar. To correct the 11-day difference, the tax year was set to start on 11 days after the old start date of 25 March. After further adjustments, it settled on 6 April.

Key Dates in the Tax Year

• 6 April — New tax year begins
• 31 May — Deadline for employers to issue P60 forms
• 5 October — Deadline to register for Self Assessment (new self-employed)
• 31 January — Self Assessment tax return deadline + payment on account
• 5 April — Tax year ends
• 31 July — Second payment on account deadline

What Does This Mean for You?

• Your tax-free personal allowance is £12,570 per tax year
• National Insurance is calculated per tax year
• ISA allowances (£20,000) reset on 6 April
• Pension contribution limits reset on 6 April

How Tax Is Calculated

UK income tax is progressive:

National Insurance Bands

National Insurance (NI) is separate from income tax:

• Primary Threshold: 8% on earnings between £12,570 and £50,270
• Upper Earnings Limit: 2% on earnings above £50,270

Understanding the tax year is part of everyday life in the UK. Learn more in our guides on payslips and P60s.