Don’t Miss These Key Tax Deadlines: Guide HMRC-Compliance in 2025/26

Tax deadlines can be daunting. miss one, and you could face costly penalties or interest charges from HMRC. Staying on top of your tax calendar doesn’t need to be stressful, though! With the right reminders and professional support, you can keep your business compliant and focused on growth. Here’s our simple guide to the key UK tax deadlines every business owner and contractor should know for 2025/26.

Key Tax Deadlines for 2025/26 You Can’t Afford to Miss

Self Assessment Deadlines

• Register for Self Assessment: 5 October 2025
  If you started self-employment or need to file a tax return for the first time, registering by this date is crucial to avoid penalties.
• Paper Tax Return Deadline: 31 October 2025
  Paper returns must be submitted by this date.
• Online Tax Return Deadline: 31 January 2026
  Online returns must be filed by this date to avoid late filing penalties.
• Payment Deadline: 31 January 2026
  Any tax owed for the 2024/25 tax year must be paid by this date.

PAYE and National Insurance Contributions (NICs)

• PAYE and NIC payments for the previous month are generally due by the 22nd of the following month (if paying electronically).
  Example: September 2025 payments are due by 22 October 2025.
• Employers must also submit monthly payroll reports to HMRC via RTI (Real Time Information).

VAT Return and Payment Deadlines

• VAT returns and payments are usually due one calendar month and 7 days after the VAT period ends. For example, for VAT quarters ending 30 September 2025, returns and payments are due by 7 November 2025.
• If you’re on the VAT Annual Accounting Scheme or Monthly payments, check your specific deadlines.

Construction Industry Scheme (CIS) Returns

• CIS monthly returns must be submitted by the 19th of the month following the deductions.
  For September 2025 deductions, the deadline is 19 October 2025.
  

Corporation Tax Deadlines

• Corporation Tax for companies with a 31 December 2024 year-end is due by 1 October 2025 (9 months and 1 day after year-end).

Tips to Stay On Track With Your Tax Deadlines

• Set Reminders: Use digital calendars or accounting software alerts to track important dates.
• Pay Electronically: Electronic payments are quicker and often offer a later deadline than paper payments.
• Keep Accurate Records: Well-organised records throughout the year make filing easier and reduce the chance of errors.
• Plan Ahead: Don’t leave your tax returns and payments until the last minute—get ahead of deadlines to avoid stress.

How We Can Help

Our team offers comprehensive support to keep your business HMRC-compliant, including bookkeeping, payroll, tax filing, and personalised reminders. Outsourcing your tax administration to us means less hassle and more time to focus on growing your business.

Contact us today for a personalised tax calendar and expert support tailored to your needs.