UK Tax Year Dates: Key Deadlines Explained

UK tax year dates shape every financial decision you make as a taxpayer. These dates run from 6 April to 5 April each year — a cycle set by HMRC that is distinct from the standard calendar year.

Knowing your UK tax year dates means you can meet HMRC deadlines, protect your allowances, and avoid unnecessary penalties. Miss a key date and a tax relief you are entitled to may be lost permanently.

This guide sets out the UK tax year dates that apply every year. It covers the new tax year start, the tax year end April 5, self assessment deadlines, and end of year planning options. Where relevant, the 2026/27 tax year is used as a worked example to show how the dates fall in practice.

Whether you pay tax through PAYE or complete a self assessment return, UK tax year dates affect your finances throughout the year. Reviewing UK tax year dates each April is one of the most practical steps you can take.

Understanding UK tax year dates helps you plan pension contributions, ISA savings, and rebate claims before key HMRC deadlines pass.

Why Does the UK Tax Year Start on 6 April?

The 6 April start date is a historical quirk dating back to 1752. Britain switched from the Julian calendar to the Gregorian calendar that year, losing eleven days in the process.

At the time, the tax year started on 25 March — Lady Day, one of the traditional quarter days.

To avoid losing tax revenue from those missing days, the Treasury shifted the year-end forward to 5 April. A further one-day adjustment in 1800 pushed it to the 6 April start that remains in place today.

No other major economy uses this date. Most countries follow either the calendar year or a fixed government financial year.

The UK financial year for government accounting runs from 1 April to 31 March — different again from the personal tax year.

UK Tax Year Dates: Start and End

The UK tax year start date is always 6 April. The tax year end is always 5 April the following year. This 12-month cycle repeats every year without change.

At the start of each new year, HMRC resets most tax-free allowances. Any unused portion from the previous year is lost. This applies to your personal allowance, ISA allowance, and dividend allowance.

Knowing these UK financial year dates in advance means you can plan around them rather than react when deadlines have already passed.

When Does the New Tax Year Begin?

The new tax year April 6 is when HMRC opens new filing windows and resets your allowances. From 6 April, you can submit PAYE tax rebate claims relating to the previous tax year.

A fresh set of allowances becomes available from this date each year. This includes your personal allowance, ISA tax allowance, and pension annual allowance.

6 April is also the earliest date you can file your self assessment return for the tax year that just ended.

Filing early gives you more time to prepare, reduces the risk of missing the January deadline, and means you know your tax bill well in advance of when payment is due.

If you are self-employed, 6 April marks the start of your new trading year for income tax purposes. This applies even if your business accounts end on a different date.

Tax Year End April 5: What to Know

Tax year end April 5 is the cut-off for a wide range of reliefs and claims. For employees under PAYE, it is when your employer finalises your income and deductions for the P60.

PAYE tax rebate claims are generally accepted for up to four tax years. Once a tax year falls outside that window, the opportunity to reclaim is typically lost. Being aware of this each year helps you act before the deadline passes.

For example, when the 2026/27 tax year ends on 5 April 2027, claims relating to the 2022/23 tax year close at the same time. The same four-year rule applies in every tax year.

Self Assessment Filing Deadline

The self assessment filing deadline varies by submission method and applies each year in the same way.

The key dates are:

• Online self assessment returns: due by 31 January following the end of the tax year.
• Paper self assessment returns: due by 31 October following the end of the tax year.
• 30 December: a third online deadline applies if you are employed and want HMRC to collect tax owed through your PAYE tax code rather than a direct payment. Your tax bill must be under £3,000 to use this option.
• Self assessment registration for new filers: due by 5 October following the end of the tax year.

As a worked example, for the 2026/27 tax year the online deadline falls on 31 January 2028, the paper deadline on 31 October 2027, and the 30 December PAYE coding option on 30 December 2027.

If HMRC issues a return to you directly, a three-month deadline applies from the issue date. Missing the online tax return deadline brings an immediate £100 penalty. Further charges may follow if the return remains outstanding beyond three months.

How Payments on Account Work

The payment on account deadline applies where the previous year’s self assessment bill exceeded £1,000. HMRC splits the estimated liability into two advance payments, due at the same points each year.

The first payment on account falls on 31 January, alongside the online filing deadline. The second falls on 31 July.

In January, two amounts may fall due together: the previous year’s balance and the first advance payment for the current year. For the 2026/27 tax year, the second payment on account falls on 31 July 2027.

If you expect your income to be lower than the previous year, you may be able to apply to HMRC to reduce your payments on account.

Reducing them by too much may result in interest being charged on any shortfall, so estimating your likely income carefully before making a request is advisable.

Self Employed Tax Deadlines UK

Self employed tax deadlines UK extend well beyond the January filing date. The pattern is the same each year. The dates relevant to sole traders include:

• 5 October: deadline to register for self assessment if newly self-employed.
• 30 December: online filing option for employed people who also have self-employed income under £3,000.
• 31 October: paper self assessment deadline.
• 31 January: online self assessment deadline and first payment on account.
• 31 July: second payment on account.

The P60 deadline of 31 May requires employers to give year-end summaries to each employee. The P11D filing date UK is 6 July each year, covering benefits and expenses provided outside of payroll.

Sole trader tax dates are worth noting at the start of each tax year to avoid last-minute pressure around filing and payment.

VAT and Corporation Tax Deadlines

For VAT-registered businesses, the VAT return deadline UK falls one month and seven days after each VAT period ends. Most businesses file quarterly, so this pattern repeats four times a year.

Under Making Tax Digital, all VAT submissions must go through HMRC-compatible software. Manual portal entry is no longer available for most registered businesses.

The corporation tax deadline UK follows a different timetable from self assessment. Companies pay corporation tax nine months and one day after the accounting period ends. The company tax return is due within twelve months of that same period end.

As an example, a company with a 31 December 2026 year end pays corporation tax by 1 October 2027 and files its return by 31 December 2027. The same formula applies for any accounting period end date.

UK Tax Year Dates for Your Diary

The following UK financial year dates cover the main HMRC key dates each year, using 2026/27 as a worked example.

These dates follow the same annual pattern regardless of which tax year you are in:

• 6 April: Start of the new tax year. New allowances begin. Earliest date to file the previous year’s self assessment return.
• 31 May: P60 deadline — employers issue P60s to all employees.
• 6 July: P11D filing date UK — benefits and expenses forms due to HMRC.
• 31 July: Second payment on account for the previous tax year.
• 5 October: Self assessment registration deadline for new filers.
• 31 October: Paper self assessment deadline for the previous tax year.
• 30 December: Online filing deadline to pay tax via PAYE coding (bill under £3,000).
• 31 January: Online self assessment deadline and first payment on account.
• 5 April: Tax year end. Final chance to use current-year allowances.

For 2026/27 specifically, the online self assessment deadline falls on 31 January 2028 and the tax year ends on 5 April 2027. Every other tax year typically follows the same structure.

End of Tax Year Planning UK

End of tax year planning UK means reviewing your finances before 5 April so allowances are not left unused. Three areas are worth checking at the end of every tax year.

Your ISA allowance of up to £20,000 per person cannot be carried forward. Any unused portion is permanently lost at the tax year end, whether that is 5 April 2027 or any other year.

Your pension annual allowance may allow tax-relieved contributions up to that years threshold, or 100% of earnings if that is lower.

Unused pension allowance from the previous three tax years may be available under carry forward rules in some circumstances. A tax adviser can help assess whether this applies to you.

An End of Year Tax Checklist

Before every 5 April, it may be worth checking whether your tax code is correct and reflects your current income. Confirming your ISA allowance has been used, where appropriate, is also a useful step.

Reviewing HMRC records via your personal tax account helps identify discrepancies early. PAYE tax rebate entitlement from the past four tax years should also be considered before the window closes.

Taking these steps before the new tax year start means you arrive at each 6 April with your affairs in order.

Final Thoughts

UK tax year dates run from 6 April to 5 April every year, with HMRC deadlines falling at the same points throughout each cycle.

The self assessment filing deadline, payment on account dates, and end of year allowances follow their own timetable but repeat in the same pattern annually.

Staying aware of these dates — whatever tax year you are in — helps protect your entitlements and reduces the risk of avoidable penalties that can only be cancelled if you have a reasonable excuse.

For further information on income tax and rebate timescales, visit our income tax rebates and tax refunds page.

Key UK Tax Year Dates Takeaways

• UK tax year dates run from 6 April to 5 April every year — a pattern dating back to Britain’s 1752 calendar change.
• The self assessment filing deadline is 31 January for online returns, 31 October for paper returns, and 30 December if collecting tax via PAYE coding.
• The payment on account deadline falls on 31 January and 31 July each year — and may be reducible if your income is lower than the previous year.
• Unused allowances — including your ISA and dividend allowance — cannot be carried forward once the tax year ends on 5 April.
• You can file your self assessment return from 6 April — filing early avoids the January rush and confirms your bill sooner.
• End of tax year planning UK before 5 April may help you make full use of allowances before they reset.

Frequently Asked Questions: UK Tax Year Dates

When does the UK tax year start?

The UK tax year starts on 6 April every year. On this date, HMRC resets most tax-free allowances including the personal allowance, ISA allowance, and dividend allowance. The 2026/27 tax year, for example, started on 6 April 2026.

Why does the UK tax year start on 6 April?

The 6 April start date traces back to 1752 when Britain switched from the Julian to the Gregorian calendar. To avoid losing tax revenue from the eleven days lost in the switch, the Treasury moved the tax year-end forward from 25 March. A further adjustment in 1800 resulted in the 6 April start that has remained in place ever since.

When does the UK tax year end?

The UK tax year ends on 5 April every year. Unused allowances — including the ISA allowance — cannot be carried forward beyond this date. The 2026/27 tax year ends on 5 April 2027.

What are the self assessment filing deadlines?

There are three online self assessment deadlines to be aware of. The standard online deadline is 31 January following the tax year end. The paper return deadline is 31 October. A third deadline of 30 December applies if you are employed and want HMRC to collect any tax owed through your PAYE tax code, provided the bill is under £3,000.

Can I reduce my payments on account?

Yes, in some circumstances. If you expect your income to be lower than the previous tax year, you may be able to apply to HMRC to reduce your payments on account. If the reduction is too large and you end up underpaying, HMRC may charge interest on the difference. Estimating your income carefully before making any change is advisable.