Tax diary: October and November 2026

1 October 2026 - Corporation Tax payment is due for companies with an accounting period ending 31 December 2025, unless the company is required to make quarterly instalment payments.

5 October 2026 - Deadline for notifying HMRC of a new liability to Income Tax or Capital Gains Tax for the 2025-26 tax year. This may include registering for Self Assessment if you became self-employed, started receiving taxable rental income or received other income or gains that have not already been taxed.

7 October 2026 - VAT returns and payments are normally due for accounting periods ending 31 August 2026, unless a different deadline applies. Businesses paying by Direct Debit should allow sufficient time for HMRC to collect the payment.

19 October 2026 - PAYE, employee and employer National Insurance contributions, student loan deductions and Construction Industry Scheme deductions are due for the month ended 5 October 2026 if payment is made by post.

19 October 2026 - Deadline for submitting the CIS300 monthly return for the month ended 5 October 2026.

22 October 2026 - Electronic payments of PAYE, National Insurance contributions, student loan deductions and CIS deductions are due for the month ended 5 October 2026.

22 October 2026 - Electronic payment deadline for tax and Class 1B National Insurance contributions due under a PAYE Settlement Agreement for the 2025-26 tax year. The deadline is 19 October 2026 if payment is not made electronically.

31 October 2026 - Deadline for submitting a paper Self Assessment tax return for the year ended 5 April 2026. Taxpayers who miss the paper filing deadline can normally file online by 31 January 2027 instead.

31 October 2026 - Corporation Tax returns are due for companies with an accounting period ending 31 October 2025.

31 October 2026 - Companies House accounts are due for private companies with an accounting period ending 31 January 2026. Different deadlines apply to a company’s first accounts.

31 October 2026 - Plastic Packaging Tax returns and payments are due for the quarter ended 30 September 2026 where the business is registered for the tax.

1 November 2026 - Corporation Tax payment is due for companies with an accounting period ending 31 January 2026, unless the company is required to make quarterly instalment payments.

7 November 2026 - VAT returns and payments are normally due for accounting periods ending 30 September 2026, unless a different deadline applies. Businesses paying by Direct Debit should allow sufficient time for HMRC to collect the payment.

19 November 2026 - PAYE, employee and employer National Insurance contributions, student loan deductions and Construction Industry Scheme deductions are due for the month ended 5 November 2026 if payment is made by post.

19 November 2026 - Deadline for submitting the CIS300 monthly return for the month ended 5 November 2026.

22 November 2026 - Electronic payments of PAYE, National Insurance contributions, student loan deductions and CIS deductions are due for the month ended 5 November 2026. As 22 November 2026 falls on a Sunday, businesses should arrange payment early enough for the cleared funds to reach HMRC by the deadline.

30 November 2026 - Corporation Tax returns are due for companies with an accounting period ending 30 November 2025.

30 November 2026 - Companies House accounts are due for private companies with an accounting period ending 28 February 2026. Different deadlines apply to a company’s first accounts.