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