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.