Running a small business in the UK means wearing many hats from marketing, sales, customer service, and everything in between. But one area that you can’t afford to overlook is your statutory and tax deadlines. Missing them can lead to unnecessary stress, penalties, and even cash flow problems.
At Accountants247 Glasgow South, we want to give you a clear, simple overview of the key deadlines coming up over the next year, so you can stay compliant and avoid any nasty surprises.
Self-Assessment Deadlines
- 5 October 2025
If you became self-employed or had new untaxed income between April 2024 and April 2025, you must register for Self-Assessment by this date. - 31 October 2025
This is the deadline for submitting your paper tax return for the 2024–25 tax year. Very few businesses use paper now, but if you still do, mark this date clearly. - 31 January 2026
Perhaps the most important deadline of the year. By this date you must:- File your online Self-Assessment tax return for 2024–25
- Pay any tax owed for the year
- Make your first payment on account for the 2025–26 tax year
- 31 July 2026
This is when your second payment on account for 2025–26 is due.
Tip: Always budget for your January and July payments in advance—too many small businesses get caught short on cash flow.
PAYE & Payroll Deadlines
If you have employees, there are several payroll-related deadlines to keep in mind:
- 19 April 2026 – Final PAYE submission (Real Time Information) for the 2025–26 tax year.
- 22 April 2026 – Final PAYE payment deadline if you pay electronically.
- 31 May 2026 – You must issue P60s to all employees, summarising their pay and deductions.
- 6 July 2026 – Deadline to submit P11D forms for any employee benefits (e.g. company cars, health insurance).
VAT Returns
If your business is VAT-registered, VAT returns and payments are due 1 month and 7 days after the end of each quarter. For example:
- Quarter ending 30 June → VAT return due 7 August
- Quarter ending 30 September → VAT return due 7 November
Tip: Making Tax Digital (MTD) means you must keep digital records and submit VAT returns through compatible software.
Limited Companies: Accounts & Corporation Tax
For those trading as a limited company, your obligations differ from sole traders:
- Annual accounts must be filed with Companies House within 9 months of your financial year end.
- Corporation Tax payment is due 9 months and 1 day after the end of your accounting period.
- The Company Tax Return (CT600) is due 12 months after the accounting period.
💡 Because company year-ends vary, your specific deadlines will depend on your incorporation date and chosen accounting period.
Key Tax Year Dates
- 5 April 2026 – End of the 2025–26 tax year
- 6 April 2026 – Start of the 2026–27 tax year
From April 2026, Making Tax Digital for Income Tax begins for sole traders and landlords with income over £50,000. This means quarterly digital submissions to HMRC instead of just one annual tax return.
Tax deadlines can feel overwhelming, but with some planning and the right support, they don’t have to be. Our advice:
- Put these dates in your calendar now
- Keep your bookkeeping up to date each month
- Set aside funds regularly for VAT and tax bills
- Ask us for reminders and support
Staying on top of these obligations will help your business run smoothly and avoid unwanted penalties. Talk to our helpful Glasgow team today here.