1 March 2024 - Due date for Corporation Tax due for the year ended 31 May 2023. 2 March 2024 – Self-Assessment tax for 2022-23 paid after this date will incur a 5% surcharge unless liabilities are cleared by 1 April 2024, or an agreement has been reached with HMRC under their time to pay facility by the same date. 19 March 2024 - PAYE and NIC deductions due for month ended 5 March 2024 (If you pay your tax electronically the due date is 22 March 2024). 19 March 2024 - Filing deadline for the CIS300 monthly return for the month ended 5 March 2024. 19 March 2024 - CIS tax deducted for the month ended 5 March 2024 is payable by today. 1 April 2024 - Due date for corporation tax due for the year ended 30 June 2023. 19 April 2024 - PAYE and NIC deductions due for month ended 5 April 2024. (If you pay your tax electronically the due date is 22 April 2024). 19 April 2024 - Filing deadline for the CIS300 monthly return for the month ended 5 April 2024. 19 April 2024 - CIS tax deducted for the month ended 5 April 2024 is payable by today. 30 April 2024 – 2022-23 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 | 07-02-2024Tax Diary March/April 2024