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.

Source:HM Revenue & Customs| 10-09-2026

Tax Diary September/October 2026

1 September 2026 – Due date for corporation tax due for the year ended 30 November 2025.

19 September 2026 – PAYE and NIC deductions due for month ended 5 September 2026. (If you pay your tax electronically the due date is 22 September 2026)

19 September 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 September 2026. 

19 September 2026 – CIS tax deducted for the month ended 5 September 2026 is payable by today.

1 October 2026 – Due date for Corporation Tax due for the year ended 31 December 2025.

19 October 2026 – PAYE and NIC deductions due for month ended 5 October 2026. (If you pay your tax electronically the due date is 22 October 2026)

19 October 2026 – Filing deadline for the CIS monthly return for the month ended 5 October 2026. 

19 October 2026 – CIS tax deducted for the month ended 5 October 2026 is payable by today.

31 October 2026 – Latest date you can file a paper version of your 2025-26 self-assessment tax return.

Source:HM Revenue & Customs| 04-08-2026

Tax Diary August/September 2026

1 August 2026 – Due date for Corporation Tax due for the year ended 31 October 2025.

19 August 2026 – PAYE and NIC deductions due for the month ended 5 August 2026. (If you pay electronically, the due date is 22 August 2026.)

19 August 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 August 2026.

19 August 2026 – CIS tax deducted for the month ended 5 August 2026 is payable by today.

1 September 2026 – Due date for Corporation Tax due for the year ended 30 November 2025.

19 September 2026 – PAYE and NIC deductions due for the month ended 5 September 2026. (If you pay electronically, the due date is 22 September 2026.)

19 September 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 September 2026.

19 September 2026 – CIS tax deducted for the month ended 5 September 2026 is payable by today.

Source:HM Revenue & Customs| 07-07-2026

Tax Diary July/August 2026

1 July 2026 – Due date for corporation tax due for the year ended 30 September 2025.

6 July 2026 – Complete and submit forms P11D return of benefits and expenses and P11D(b) return of Class 1A NICs for 2025-26.

19 July 2026 – Pay Class 1A NICs for 2025-26 (by the 22 July 2026 if paid electronically).

19 July 2026 – PAYE and NIC deductions due for month ended 5 July 2026. (If you pay your tax electronically the due date is 22 July 2026).

19 July 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 July 2026. 

19 July 2026 – CIS tax deducted for the month ended 5 July 2026 is payable by today.

1 August 2026 – Due date for corporation tax due for the year ended 31 October 2025.

19 August 2026 – PAYE and NIC deductions due for month ended 5 August 2026. (If you pay your tax electronically the due date is 22 August 2026)

19 August 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 August 2026. 

19 August 2026 – CIS tax deducted for the month ended 5 August 2026 is payable by today.

Source:HM Revenue & Customs| 07-06-2026

Tax Diary June/July 2026

1 June 2026 – Due date for corporation tax due for the year ended 31 August 2025.

19 June 2026 – PAYE and NIC deductions due for month ended 5 June 2026. (If you pay your tax electronically the due date is 22 June 2026).

19 June 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 June 2026. 

19 June 2026 – CIS tax deducted for the month ended 5 June 2026 is payable by today.

1 July 2026 – Due date for corporation tax due for the year ended 30 September 2025.

6 July 2026 – Complete and submit forms P11D return of benefits and expenses and P11D(b) return of Class 1A NICs.

19 July 2026 – Pay Class 1A NICs (by the 22 July 2026 if paid electronically).

19 July 2026 – PAYE and NIC deductions due for month ended 5 July 2026. (If you pay your tax electronically the due date is 22 July 2026).

19 July 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 July 2026. 

19 July 2026 – CIS tax deducted for the month ended 5 July 2026 is payable by today.

Source:HM Revenue & Customs| 06-05-2026

Tax Diary May/June 2026

1 May 2026 – Due date for corporation tax due for the year ended 30 July 2025.

19 May 2026 – PAYE and NIC deductions due for month ended 5 May 2026. (If you pay your tax electronically the due date is 22 May 2026).

19 May 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 May 2026. 

19 May 2026 – CIS tax deducted for the month ended 5 May 2026 is payable by today.

31 May 2026 – Ensure all employees have been given their P60s for the 2025/26 tax year.

1 June 2026 – Due date for corporation tax due for the year ended 31 August 2025.

19 June 2026 – PAYE and NIC deductions due for month ended 5 June 2026. (If you pay your tax electronically the due date is 22 June 2026).

19 June 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 June 2024. 

19 June 2026 – CIS tax deducted for the month ended 5 June 2026 is payable by today.

Source:HM Revenue & Customs| 12-04-2026

Tax Diary April/May 2026

1 April 2026 – Due date for corporation tax due for the year ended 30 June 2025.

19 April 2026 – PAYE and NIC deductions due for month ended 5 April 2026 (If you pay your tax electronically the due date is 22 April 2026).

19 April 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 April 2026.

19 April 2026 – CIS tax deducted for the month ended 5 April 2026 is payable by today.

30 April 2026 – 2024-25 tax returns filed after this date will be subject to an additional £10 per day late filing penalty for a maximum of 90 days.

1 May 2026 – Due date for corporation tax due for the year ended 30 July 2025.

19 May 2026 – PAYE and NIC deductions due for month ended 5 May 2026. (If you pay your tax electronically the due date is 22 May 2026).

19 May 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 May 2026.

19 May 2026 – CIS tax deducted for the month ended 5 May 2026 is payable by today.

31 May 2026 – Ensure all employees have been given their P60s for the 2025/26 tax year.

Source:HM Revenue & Customs| 12-03-2026

Tax Diary March/April 2026

1 March 2026 – Due date for Corporation Tax due for the year ended 31 May 2025.

2 March 2026 – Self-Assessment tax for 2024-25 paid after this date will incur a 5% surcharge unless liabilities are cleared by 1 April 2026, or an agreement has been reached with HMRC under their time to pay facility by the same date.

19 March 2026 – PAYE and NIC deductions due for month ended 5 March 2026 (If you pay your tax electronically the due date is 22 March 2026).

19 March 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 March 2026.

19 March 2026 – CIS tax deducted for the month ended 5 March 2026 is payable by today.

1 April 2026 – Due date for corporation tax due for the year ended 30 June 2025.

19 April 2026 – PAYE and NIC deductions due for month ended 5 April 2026. (If you pay your tax electronically the due date is 22 April 2026).

19 April 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 April 2026.

19 April 2026 – CIS tax deducted for the month ended 5 April 2026 is payable by today.

30 April 2026 – 2024-25 tax returns filed after this date will be subject to an additional £10 per day late filing penalty for a maximum of 90 days.

Source:HM Revenue & Customs| 10-02-2026

Tax Diary February/March 2026

1 February 2026 – Due date for Corporation Tax payable for the year ended 30 April 2025.

19 February 2026 – PAYE and NIC deductions due for month ended 5 February 2026. (If you pay your tax electronically the due date is 22 February 2026)

19 February 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 February 2026.

19 February 2026 – CIS tax deducted for the month ended 5 February 2026 is payable by today.

1 March 2026 – Due date for Corporation Tax due for the year ended 31 May 2025.

2 March 2026 – Self-Assessment tax for 2024-25 paid after this date will incur a 5% surcharge unless liabilities are cleared by 1 April 2026, or an agreement has been reached with HMRC under their time to pay facility by the same date.

19 March 2026 – PAYE and NIC deductions due for month ended 5 March 2026 (If you pay your tax electronically the due date is 22 March 2026).

19 March 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 March 2026.

19 March 2026 – CIS tax deducted for the month ended 5 March 2026 is payable by today.

Source:HM Revenue & Customs| 15-01-2026

Tax Diary January/February 2026

1 January 2026 – Due date for Corporation Tax due for the year ended 31 March 2025

19 January 2026 – PAYE and NIC deductions due for month ended 5 January 2026. (If you pay your tax electronically the due date is 22 January 2026).

19 January 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 January 2026.

19 January 2026 – CIS tax deducted for the month ended 5 January 2026 is payable by today.

31 January 2026 – Last day to file 2024-25 self-assessment tax returns online.

31 January 2026 – Balance of self-assessment tax owing for 2024-25 due to be settled on or before today unless you have elected to extend this deadline by formal agreement with HMRC. Also due is any first payment on account for 2025-26.

1 February 2026 – Due date for Corporation Tax payable for the year ended 30 April 2025.

19 February 2026 – PAYE and NIC deductions due for month ended 5 February 2026. (If you pay your tax electronically the due date is 22 February 2026)

19 February 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 February 2026.

19 February 2026 – CIS tax deducted for the month ended 5 February 2026 is payable by today.

Source:HM Revenue & Customs| 08-12-2025

Tax Diary December 2025/January 2026

1 December 2025 – Due date for Corporation Tax payable for the year ended 28 February 2025.

19 December 2025 – PAYE and NIC deductions due for month ended 5 December 2025. (If you pay your tax electronically the due date is 22 December 2025).

19 December 2025 – Filing deadline for the CIS300 monthly return for the month ended 5 December 2025. 

19 December 2025 – CIS tax deducted for the month ended 5 December 2025 is payable by today.

30 December 2025 – Deadline for filing 2024-25 self-assessment tax returns online to include a claim for under payments to be collected via tax code in 2026-27.

1 January 2026 – Due date for Corporation Tax due for the year ended 31 March 2025.

19 January 2026 – PAYE and NIC deductions due for month ended 5 January 2026. (If you pay your tax electronically the due date is 22 January 2026).

19 January 2026 – Filing deadline for the CIS300 monthly return for the month ended 5 January 2026. 

19 January 2026 – CIS tax deducted for the month ended 5 January 2026 is payable by today.

31 January 2026 – Last day to file 2023-24 self-assessment tax returns online.

31 January 2026 – Balance of self-assessment tax owing for 2024-25 due to be settled on or before today unless you have elected to extend this deadline by formal agreement with HMRC. Also due is any first payment on account for 2025-26.

Source:HM Revenue & Customs| 06-11-2025

Tax Diary November/December 2025

1 November 2025 – Due date for Corporation Tax due for the year ended 31 January 2025.

19 November 2025 – PAYE and NIC deductions due for month ended 5 November 2024. (If you pay your tax electronically the due date is 22 November 2025.)

19 November 2025 – Filing deadline for the CIS300 monthly return for the month ended 5 November 2025. 

19 November 2025 – CIS tax deducted for the month ended 5 November 2025 is payable by today.

1 December 2025 – Due date for Corporation Tax payable for the year ended 28 February 2025.

19 December 2025 – PAYE and NIC deductions due for month ended 5 December 2025. (If you pay your tax electronically the due date is 22 December 2025).

19 December 2025 – Filing deadline for the CIS300 monthly return for the month ended 5 December 2025. 

19 December 2025 – CIS tax deducted for the month ended 5 December 2025 is payable by today.

30 December 2025 – Deadline for filing 2024-25 self-assessment tax returns online to include a claim for under payments to be collected via tax code in 2026-27.

Source:HM Revenue & Customs| 07-10-2025

Tax Diary October/November 2025

1 October 2025 – Due date for Corporation Tax due for the year ended 31 December 2024.

19 October 2025 – PAYE and NIC deductions due for month ended 5 October 2025. (If you pay your tax electronically the due date is 22 October 2025.)

19 October 2025 – Filing deadline for the CIS300 monthly return for the month ended 5 October 2025. 

19 October 2025 – CIS tax deducted for the month ended 5 October 2025 is payable by today.

31 October 2025 – Latest date you can file a paper version of your 2024-25 self-assessment tax return.

1 November 2025 – Due date for Corporation Tax due for the year ended 31 January 2025.

19 November 2025 – PAYE and NIC deductions due for month ended 5 November 2025. (If you pay your tax electronically the due date is 22 November 2025.)

19 November 2025 – Filing deadline for the CIS300 monthly return for the month ended 5 November 2025. 

19 November 2025 – CIS tax deducted for the month ended 5 November 2025 is payable by today.

Source:HM Revenue & Customs| 07-09-2025

Tax Diary September/October 2025

1 September 2025 – Due date for corporation tax due for the year ended 30 November 2024.

19 September 2025 – PAYE and NIC deductions due for month ended 5 September 2025. (If you pay your tax electronically the due date is 22 September 2025)

19 September 2025 – Filing deadline for the CIS300 monthly return for the month ended 5 September 2025. 

19 September 2025 – CIS tax deducted for the month ended 5 September 2025 is payable by today.

1 October 2025 – Due date for Corporation Tax due for the year ended 31 December 2024.

19 October 2025 – PAYE and NIC deductions due for month ended 5 October 2025. (If you pay your tax electronically the due date is 22 October 2025)

19 October 2025 – Filing deadline for the CIS300 monthly return for the month ended 5 October 2025. 

19 October 2025 – CIS tax deducted for the month ended 5 October 2025 is payable by today.

31 October 2025 – Latest date you can file a paper version of your 2024-25 self-assessment tax return.

Source:HM Revenue & Customs| 20-08-2025

Tax Diary August/September 2025

1 August 2025 – Due date for corporation tax due for the year ended 31 October 2024.

19 August 2025 – PAYE and NIC deductions due for month ended 5 August 2025 (If you pay your tax electronically the due date is 22 August 2025)

19 August 2025 – Filing deadline for the CIS300 monthly return for the month ended 5 August 2025. 

19 August 2025 – CIS tax deducted for the month ended 5 August 2025 is payable by today.

1 September 2025 – Due date for corporation tax due for the year ended 30 November 2024.

19 September 2025 – PAYE and NIC deductions due for month ended 5 September 2025. (If you pay your tax electronically the due date is 22 September 2025)

19 September 2025 – Filing deadline for the CIS300 monthly return for the month ended 5 September 2025. 

19 September 2025 – CIS tax deducted for the month ended 5 September 2025 is payable by today.

Source:HM Revenue & Customs| 08-07-2025