When does the UK tax year start and end

The UK tax year for individuals starts on 6 April and ends on the following 5 April, as section 4 of the Income Tax Act 2007 states. The 2026 to 2027 tax year runs from 6 April 2026 to 5 April 2027. The odd date is a leftover from the old Lady Day quarter day and the 1752 calendar change, and most personal tax deadlines, from Self Assessment registration to employer P60s, are counted from it.

What dates does the 2026 to 2027 tax year cover?

Section 4(3) ITA 2007 says a tax year begins on 6 April and ends on the following 5 April. Section 4(4) fixes the naming convention: “the tax year 2007-08” means the year beginning on 6 April 2007, and other years are read the same way. So the 2026 to 2027 tax year is 6 April 2026 to 5 April 2027, and the 2027 to 2028 year starts on 6 April 2027.

Section 4(5) adds that every income tax assessment must be made for a tax year. Income tax, Capital Gains Tax for individuals and most personal allowances work on this year. gov.uk, for example, describes the Personal Savings Allowance as given each tax year (6 April to 5 April), and says the maximum you can save in ISAs in the 2026 to 2027 tax year is £20,000.

Why does the tax year start on 6 April?

The Chartered Institute of Taxation explains that the tax year originally began on Lady Day, 25 March, a religious festival and one of the traditional quarter days. When Britain moved from the Julian to the Gregorian calendar in 1752, the year end moved to 5 April to make up for the days lost in the change. It moved again to 6 April in 1800 because of a mismatch over leap years between the old and new calendars.

The CIOT notes that the UK is very unusual in having a 5 April year end, as most other countries, including the USA, France, Germany and Ireland, use the calendar year. The CIOT also reports that in 2021 the Office of Tax Simplification found clear advantages in a different year end, keeping 31 December on the table as a long term option and recommending that self employed people and individual landlords be allowed to use 31 March in the shorter term. The statutory date in section 4 has not changed.

Is the tax year the same for companies?

No. Corporation Tax rates are set for “financial years”. The Interpretation Act 1978 (Schedule 1) defines a financial year, for central taxes and finance, as the twelve months ending with 31 March, and section 1119 of the Corporation Tax Act 2010 says “the financial year 2010” means the financial year beginning with April 2010. gov.uk’s Corporation Tax rates guidance refers to the rate “for the financial year starting 1 April”.

A company is then taxed on its own accounting periods, which can end on any date, and where an accounting period straddles 1 April the profits are split between the two financial years. See Corporation Tax deadlines for how a company’s filing and payment dates are counted from its own year end rather than from 5 April.

How does the tax year affect the self employed?

Since basis period reform, sole traders and partners are taxed on the profits of the tax year itself. gov.uk explains that from 6 April 2023 profits must be reported up to the tax year end even if the business accounting year ends at a different time, with 2023 to 2024 as the transition year. If the accounting year does not end on or between 31 March and 5 April, profits from two sets of accounts may need to be apportioned.

A 31 March year end is treated as matching the tax year. HMRC’s Business Income Manual (BIM81210) explains that where the accounting date falls between 31 March and 4 April inclusive, profits for the days up to 5 April are treated as nil for that year and as arising in the following year, unless the trader elects otherwise. See basis period reform explained for the transition rules.

Making Tax Digital for Income Tax follows the same idea. gov.uk sets out standard quarterly update periods that align to the tax year (6 April to 5 April) and calendar update periods for people whose accounting period runs from 1 April to 31 March, with the same update deadlines of 7 August, 7 November, 7 February and 7 May for both.

Which Self Assessment deadlines depend on the tax year?

All the main ones are counted from 5 April. Applying the rules in the Taxes Management Act 1970 to the 2026 to 2027 tax year gives:

Deadline	Date for 2026 to 2027	Rule
First payment on account	31 January 2027	Section 59A(2)(a) TMA 1970
Second payment on account	31 July 2027	Section 59A(2)(b)
Tell HMRC you need to file (if not already in Self Assessment)	5 October 2027	Section 7: within 6 months of the end of the year
Paper return	31 October 2027	Section 8(1D)(a)
Online return to have tax under £3,000 collected through your tax code	30 December 2027	gov.uk guidance
Online return and balancing payment	31 January 2028	Sections 8(1D)(b) and 59B(4)

The full list, including late notice cases, is on our Self Assessment deadlines page, and the payment side is explained in payments on account.

Which employer deadlines follow the tax year?

PAYE runs on the same year. gov.uk’s payroll annual reporting guidance says employers must report to HMRC on the previous tax year, which ends on 5 April, and prepare for the new tax year starting on 6 April. The final payroll report of the year is due on or before the employees’ payday, P60s must be given to employees by 31 May, and expenses and benefits must be reported by 6 July. For 2026 to 2027 that means P60s by 31 May 2027 and benefit returns by 6 July 2027.

Worked example: which year does it fall in?

Illustration only. Priya, an employee with some savings, earns interest that is credited on 5 April 2027. It belongs to the 2026 to 2027 tax year. Interest credited a day later, on 6 April 2027, belongs to 2027 to 2028 and uses that year’s allowances. If she starts self employment on 1 April 2027 and makes up accounts to 31 March 2028, the late accounting date rules in BIM81210 treat her profits for 1 to 5 April 2027 as arising in 2027 to 2028, so her first tax year is effectively the year to 31 March 2028.

What are the common mistakes?

• Treating 1 April as the start of the personal tax year. That is the company financial year. Individuals use 6 April.
• Assuming 31 January is the filing deadline for the year just ended. The 31 January 2027 deadline is for the 2025 to 2026 return. The 2026 to 2027 return is due by 31 January 2028.
• Missing that 5 April is the last day, not the first. Transactions on 5 April fall into the year that is ending.
• Forgetting the first payment on account falls inside the tax year. For 2026 to 2027 it is due on 31 January 2027, before the year has ended.

The UK tax deadlines calendar brings these dates together with VAT and company deadlines.

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Related Accountapedia entries

• Should a sole trader change year end to 31 March
• Annual filing calendar for a small limited company
• MTD quarterly periods and the calendar quarter election
• Your first tax year as a sole trader
• Reporting gains with the real time CGT service
• Goods in transit at the year end
• Assets under construction: when to start depreciating

Sources

• legislation.gov.uk: Act 2007 c. 3, section 4
• GOV.UK: How much is tax free
• GOV.UK: Individual savings accounts
• CIOT: Time to ditch quirky 5 april tax year end
• legislation.gov.uk: Act 1978 c. 30, schedule 1
• legislation.gov.uk: Act 2010 c. 4, section 1119
• GOV.UK: Corporation tax rates
• GOV.UK: Changes to reporting income from self employment and partnerships
• GOV.UK: Manual page BIM81210
• GOV.UK: Send quarterly updates

Reviewed by Christine Anderson, Broker, Solar Protect. Last reviewed 19 October 2026. Part of Accountapedia, the Solar Protect guide to UK tax and accounting. This page is general information, not personalised advice.