1 October 2020 - Due date for Corporation Tax due for the year ended 31 December 2019. 19 October 2020 - PAYE and NIC deductions due for month ended 5 October 2020. (If you pay your tax electronically the due date is 22 October 2020.) 19 October 2020 - Filing deadline for the CIS300 monthly return for the month ended 5 October 2020. 19 October 2020 - CIS tax deducted for the month ended 5 October 2020 is payable by today. 31 October 2020 – Latest date you can file a paper version of your 2020 Self-Assessment tax return. 1 November 2020 - Due date for Corporation Tax due for the year ended 31 January 2020. 19 November 2020 - PAYE and NIC deductions due for month ended 5 November 2020. (If you pay your tax electronically the due date is 22 November 2020.) 19 November 2020 - Filing deadline for the CIS300 monthly return for the month ended 5 November 2020. 19 November 2020 - CIS tax deducted for the month ended 5 November 2020 is payable by today. Source: HM Revenue & Customs | 16-09-2020Tax Diary October/November 2020