Running a small business means you’ve got enough on your plate without worrying about missed deadlines. So here are the crucial business and tax dates you need to know for 2026, helping you to reduce admin time and avoid unexpected fines.
At a glance: 2026 tax and business deadlines
| Date | What is due? | Who does it affect? |
| 5 April 2026 | 2025-26 tax year ends | All businesses and self-employed people |
| 6 April 2026 | MTD for ITSA begins (income over £50,000) | Sole traders and landlords |
| 6 July 2026 | P11D form deadline | Those with employees |
| 31 July 2026 | Second payment on account due | Self-assessed taxpayers |
| 5 October 2026 | Deadline to register for self-assessment | Newly self-employed people |
| 31 October 2026 | Paper tax return deadline | Those filing paper self-assessments |
| 30 December 2026 | Deadline to collect tax through PAYE | Taxpayers with PAYE income |
When does the UK tax year start and end?
The UK tax year runs from the 6 April to the 5 April the following year. Often referred to as the financial or fiscal year, it’s the period on which all your business’s financial reporting is based.
But when does the tax year end? We’re currently in the 2025-26 tax year, which ends on 5 April 2026. We’ll then enter the 2026-27 tax year.
Fun tax fact: The UK is one of the only countries in the world whose tax year doesn’t match the calendar year. This is steeped in history and is due to the UK’s change from the Julian to the Gregorian calendar in 1752.
Because of this discrepancy, it’s important to know which tax year we’re in and the key dates within it. Understanding business tax can help you with budgeting and strategy – as well as avoiding potential fines from missed deadlines.
April 2026: end of the tax year and digital tax changes
5 April 2026
The 2025-26 tax year ends on this date, so you’ll need to make sure your accounting records are up to date. It’s a good time to organise your receipts, check your expenses, and get ready for your next tax return.
6 April 2026
The 2026-27 tax year begins. This brings a major regulation change for many small businesses. Making Tax Digital for Income Tax Self Assessment (MTD for ITSA) becomes mandatory for sole traders and landlords with a qualifying income over £50,000.
Be aware: If MTD affects you, you’ll no longer be able to keep manual records. You must use compatible software to automate your accounting, keep digital records, and send quarterly tax updates to HMRC.
But don’t wait until this deadline to find or set up your software, make sure you’re all set up before this date to avoid fines and stress later down the line.
July 2026: P11D and payments on account
6 July 2026
If you’re an employer, you’ll need to give your employees a copy of their P11D form. You’ll also need to send a copy to HMRC by this date too. A P11D form is what you use to tell HMRC about any ‘benefits in kind’ you’ve given your employees.
31 July 2026
Your second payment on account is due for the 2025-26 tax year. This is an advance payment towards your upcoming income tax bill. HMRC bases this figure on your previous year’s tax bill, and it helps spread the cost of your tax across the year.
Be aware: The introduction of Making Tax Digital doesn’t affect payment on account. While MTD changes how you report your income, it doesn’t change the timing of your tax payments.
October 2026: registration and paper returns
5 October 2026
If you’ve started a business or became a landlord during the 2025-26 tax year, this is the deadline to tell HMRC. You must register for self-assessment by this date to avoid any penalties.
31 October 2026
If you prefer to file a paper tax return, HMRC must receive it by midnight on this day. But if you’re affected by MTD, you’ll no longer be able to file a paper tax return unless you’ve been given a special exemption.
December 2026: PAYE tax collection
30 December 2026
You can ask HMRC to automatically collect the tax you owe from your wages or pension. To do this, you must file your online self-assessment by 30 December. You also need to owe less than £3,000 and already pay tax through PAYE.
Preparing for the UK tax year dates
Now that you know the key tax year dates for the upcoming year, there are a few ways to help prepare:
- add these tax year dates to your calendar
- consider setting up reminders in advance to give yourself time
- familiarise yourself with the HMRC app – spend some time getting to know where everything is so there are no holdups as tax deadlines approach
- don’t wait until the end of the tax year to scramble for receipts and invoices – keep track of your income and expenses throughout the year
- check which self-employed expenses are tax deductible when saving your receipts
If you’re still unsure about paying taxes, or if your business’s taxes are more complicated, you can always consider hiring an accountant. Looking into how much an accountant costs can help you budget for this in the future.
Key tax dates FAQs
Do the dates of the tax year ever change?
While the tax year begins on the 6 April each year and doesn’t change, specific dates within the tax year could change.
Make sure you stay informed about any updates to tax laws, regulations, and deadlines within the tax year. The Autumn and Spring budgets often reveal upcoming changes. You can also follow our social channels and sign up for our newsletter to stay in the loop.
What’s the difference between the tax and the financial year?
While the terms are often used interchangeably, there’s a slight difference between tax year and financial year. The dates of the tax year are set by the UK government, while a company’s financial year is chosen by the company.
What are the most important small business tax deadlines?
Keeping track of your small business tax deadlines is the easiest way to keep your business running smoothly. Your key dates depend on your specific taxes, but you should always watch out for monthly PAYE payments and annual Self Assessment deadlines. Mark these dates on your calendar early so you never fall behind.
What happens if I miss a deadline?
If you miss a payment or filing deadline, you may face HMRC penalties. These fines can add up and hurt your bottom line. Submit your tax returns and pay any owed taxes prior to your deadlines to easily avoid these extra costs.
When are my monthly PAYE payments due?
Your PAYE payment deadlines happen every single month. If you pay by mail, your deadline is the 19th. If you pay online, you have until the 22nd. Paying online is a simple, secure way to make sure your payment arrives right on time.
What annual forms do I need to give my employees?
You must give a P60 form to all of your employees by 31 May. Additionally, if you provide expenses or benefits to your team, you need to file P11D forms by 6 July.
Did you know business insurance is tax deductible?
Business insurance (such as public liability insurance) is an allowable expense you can claim while filing your tax return – while also helping to protect your small business. Why not get a tailored quote for business insurance today and start the new tax year off right?