1 April 2019 – Due date for Corporation Tax due for the year ended 30 June 2018. 19 April 2019 – PAYE and NIC deductions due for month ended 5 April 2019. (If you pay your tax electronically the due date is 22 April 2019) 19 April 2019 – Filing deadline for the CIS300 monthly return for the month ended 5 April 2019.  19 April 2019 – CIS tax deducted for the month ended 5 April 2019 is payable by today. 30 April 2019 – 2017-18 tax returns filed after this date will be subject to an additional £10 per day late filing penalty. 1 May 2018 – Due date for Corporation Tax due for the year ended 30 July 2017. 19 May 2019 – PAYE and NIC deductions due for month ended 5 May 2019. (If you pay your tax electronically the due date is 22 May 2019) 19 May 2019 – Filing deadline for the CIS300 monthly return for the month ended 5 May 2019.  19 May 2019 – CIS tax deducted for the month ended 5 May 2019 is payable by today. 31 May 2019 – Ensure all employees have been given their P60s for the 2018-19 tax year.