UK Tax Year Dates and Tax Returns Deadlines 2026/2027

In the UK, the personal tax year runs from 6 April to 5 April and is different from the calendar year, which runs from 1 January to 31 December. Individuals use the tax year for Income Tax and Self Assessment, while limited companies normally use their own accounting periods for annual accounts and Corporation Tax.

When does the UK tax year start and end?

The UK personal tax year starts on 6 April and ends on 5 April the following year. The 2026/27 tax year therefore runs from 6 April 2026 to 5 April 2027. Individuals use this period for Income Tax and Self Assessment, while limited companies normally follow their own accounting periods for annual accounts and Corporation Tax.

What is the current tax year?

The current tax year is 2026/27, running from 6 April 2026 to 5 April 2027.

When is the deadline for filing a tax return with HMRC?

For the 2025/26 tax year, file your Self Assessment return by 31 January 2027 online or 31 October 2026 on paper.

When do you get a tax refund?

If you paid too much or too little tax by the end of the tax year on 5 April, HMRC sends you either a tax calculation letter (a P800) or a Simple Assessment letter. The letters go out between June and March of the following tax year.

How soon after the tax year ends can you file a Self Assessment tax return?

You can send your Self Assessment return any time after 5 April. Filing earlier helps you find out what you owe sooner, budget for the bill and have more time to pay by 31 January. You can also set up a payment plan if you cannot pay on time.

What happens if you miss the Self Assessment filing deadline?

If you send a required Self Assessment return late, the initial penalty is £100. After 3 months, HMRC can charge £10 per day up to a maximum of £900, with further penalties after 6 and 12 months. Late payment can also lead to separate penalties and interest.

Do you need to file a Self Assessment tax return if you already pay tax through PAYE?

Paying tax through PAYE does not necessarily mean you will never need to send a Self Assessment return. You may still need one if you were a sole trader earning more than £1,000, were a business partner, had Capital Gains Tax to pay, or received untaxed income.

How is Self Assessment changing from April 2026?

From 6 April 2026, Making Tax Digital for Income Tax applies to sole traders and landlords whose qualifying income for 2024/25 was more than £50,000. Those affected must choose and authorise Making Tax Digital software and use it to keep their records and send their updates to HMRC. The threshold falls to more than £30,000 from April 2027 and more than £20,000 from April 2028. Check your gross self-employment and property income to confirm when the rules apply to you.

What is the significance of income tax weeks in the UK?

Tax weeks ensure consistency and accuracy in the administration of taxes and contributions throughout the UK tax year.

A tax week is a successive seven-day period starting on 6th April, the beginning of the tax cycle, meaning one tax year is divided into 52–53 tax weeks. Within the UK tax system, income tax weeks are helpful in:

• Determining tax thresholds and allowances: Tax weeks help employers calculate PAYE deductions consistently for employees paid weekly.
• Aligning pay periods with employees paid weekly: Tax weeks align with weekly pay periods for many employees.
• Reporting PAYE Information: Employers use tax weeks to report employee pay and deductions to HMRC under the RTI system.
• Calculating NICs: NIC thresholds are determined per tax week, ensuring accurate deductions.

What is the significance of a tax month in the UK tax system?

A tax month runs from the 6th of one month to the 5th of the next month and is used to structure final dates and obligations as follows —

• PAYE Tax and NICs: Employers use the tax month to align employee earnings with income tax deductions and NICs from employees’ wages.
• Submission of Payroll Information to HMRC: Employers must submit payroll information, including earnings, deductions, and NICs, using the Real Time Information (RTI) system each tax month.
• Deadlines for payment of tax bills: The tax month determines the last date for employers to make PAYE and National Insurance payments to HMRC.

The tax month framework helps maintain consistency and accuracy in reporting by streamlining tax collection and compliance processes.

What are the important PAYE tax dates in the UK?

Any employer with employees must adhere to PAYE tax dates to ensure compliance with HMRC regulations and the timely payroll reporting and payments.

Non-electronic payments must normally reach HMRC by the 19th, while electronic payments must normally reach HMRC by the 22nd. Always check HMRC guidance for the most current deadlines.

What should I do before the end of the tax year 2026/27?

Before the end of the tax cycle, you must make sure you leverage reliefs and other statutory benefits available as follows:

1. Assess your tax planning opportunities that are likely to reduce your tax bill:
   • Make pension contributions: Make sure to put money into a pension scheme to get tax benefits. You can normally receive tax relief on personal pension contributions up to 100% of your relevant UK earnings, subject to the standard £60,000 annual allowance for 2026/27. A lower allowance can apply to high earners or people who have flexibly accessed a pension. Pension contributions can also reduce adjusted net income, which may affect the High Income Child Benefit Charge if your adjusted net income exceeds £60,000.
   • Utilise Individual Savings Account (ISA) allowance: An ISA is a tax-efficient savings and investment account with an annual allowance of £20,000. You can hold a cash ISA, a stocks and shares ISA, an innovative finance ISA or a Lifetime ISA, or a combination, within the same £20,000 limit.
   • Put away some money as savings for your children: For a child with no earnings, you can normally contribute £2,880 net into a pension each tax year. Basic-rate tax relief increases this to £3,600 gross. Additionally, contribute up to £9,000 per year into a Junior ISA, allowing for tax-free savings to support your child’s future financial needs.
   • Use your Capital Gains Tax (CGT) annual exempt amount: Individuals have a £3,000 annual exempt amount for the 2026/27 tax year. Consider the timing of taxable disposals and whether eligible investments can be held within an ISA, while taking professional advice where necessary.
   • If you take income from your own limited company, model the salary and dividend split before 5 April with the Your Company Formations dividend calculator, which shows the tax impact across current and previous tax years. 
2. Organise your tax records: Prepare your income statements, expenditure receipts, and other financial records. Having this paperwork on your desk or in an accounting system will make your filing process much easier and reduce the chances of errors. If that accounting system is still a spreadsheet, Xero keeps the records digital and dated so the PAYE, Self Assessment and Class 1A deadlines above are met from one place.
3. Plan to clear your tax bill: Estimate your tax liability and plan to pay it. Setting aside some money throughout the year to cover your tax bill to avoid last-minute scrambles and financial strain when your payments are due is advisable.
4. File your returns on time: Preparing early helps you meet deadlines and avoid penalties, interest charges, underpaying or overpaying tax. For the 2025/26 tax year, submit paper or online tax returns by 31 October 2026 or 31 January 2027, respectively. Filing on time requires early preparation and the timely organisation of all necessary documents. Procrastination can lead to rushed filings, which increase the likelihood of mistakes. By staying ahead of the last date and keeping your records in order, you can ensure a stress-free filing process and avoid unnecessary fines.