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.