UK Tax Deadlines for Small Business Owners in 2026

scott33587
Jan 28
3 min read

Updated: Feb 17

UK tax deadlines calendar for small business owners

Keeping track of tax deadlines is crucial for running a business in the UK. With various requirements for Self Assessment, VAT, payroll, and Corporation Tax, it can feel overwhelming. Deadlines and rules often change, adding to the complexity.

This article provides a general overview of the main UK tax dates that small business owners should be aware of in 2026. It serves as guidance only and should not replace professional or HMRC advice.

Understanding Tax Deadlines

Tax deadlines are essential for maintaining compliance. Missing them can lead to penalties and interest charges. Therefore, it’s important to stay informed about your obligations.

Self Assessment Deadlines

Many sole traders, company directors, and individuals with additional sources of income must submit a Self Assessment tax return.

In most cases:

Online Self Assessment tax returns are due by 31 January.
Any tax owed for the previous tax year is usually payable by the same date.
Some taxpayers may also need to make payments on account, with instalments typically due by 31 January and 31 July.

Late submissions or payments can result in penalties and interest charged by HMRC.

VAT Return Deadlines

Businesses registered for VAT must submit VAT returns, usually on a quarterly basis, under Making Tax Digital (MTD) rules.

VAT returns and payments are generally due one month and seven days after the end of each VAT period. However, exact dates depend on your VAT scheme and accounting period. Maintaining accurate and up-to-date records throughout the quarter can help make VAT submissions smoother and reduce the risk of errors.

PAYE and Payroll Deadlines

If your business employs staff or operates a payroll, you may need to report payroll information to HMRC under Real Time Information (RTI).

In most cases:

RTI submissions should be made on or before each payday.
PAYE and National Insurance contributions are usually payable by the 22nd of the following month when paying electronically.

HMRC may issue penalties for late submissions or payments.

Corporation Tax Deadlines

Limited companies are subject to Corporation Tax and have specific filing and payment requirements.

Typically:

Corporation Tax is payable nine months and one day after the end of the accounting period.
Company accounts and Corporation Tax returns (CT600) must generally be filed within 12 months of the period end.

Corporation Tax obligations can vary depending on a company’s circumstances, so planning ahead is essential.

Getting Support With Tax Deadlines

Tax obligations can differ based on your business structure and individual circumstances. Working with an accountant can help ensure deadlines are monitored, records are accurate, and submissions are made on time.

Barton Accountancy supports business owners in Swadlincote, Ashby-de-la-Zouch, and across the UK. We provide practical, jargon-free advice to help businesses stay compliant and organised.

If you would like guidance tailored to your situation, please get in touch to arrange a free discovery call.

Importance of Staying Informed

Staying informed about tax deadlines is vital for business success. It allows you to manage your finances effectively and avoid unnecessary penalties. Regularly reviewing your obligations can help you maintain control over your financial situation.

Planning Ahead

Planning ahead is crucial for meeting your tax obligations. Create a calendar that includes all relevant deadlines. This will help you stay organised and ensure that you never miss a due date.

Seeking Professional Help

If you find tax regulations confusing, consider seeking professional help. An accountant can provide valuable insights and assist you in navigating the complexities of tax compliance. They can also help you identify potential savings and ensure that you are taking advantage of all available allowances.

Conclusion

In conclusion, understanding and keeping track of UK tax deadlines is essential for small business owners. By staying informed and organised, you can avoid penalties and maintain compliance.

If you need assistance, don't hesitate to reach out to professionals who can guide you through the process. Remember, being proactive about your tax obligations will empower you to make smart decisions and grow your business without financial stress.