14 March 2021

• EC sales list

  Deadline for paper monthly or quarterly return filing.

19 March 2021

• Monthly postal PAYE/class 1 NICs/student loan payment

  If you pay by cheque through the post, monthly payments due for PAYE, class 1 NICs and student loan deductions from February 2021.

• CIS return

  Construction Industry Scheme: monthly return due for period up to 5th of previous month.

21 March 2021

• EC sales list

  Deadline for online monthly or quarterly return filing.

• Intrastat

  Due date for payment of supplementary declarations for February 2021.

22 March 2021

• Monthly electronic PAYE/class 1 NICs/student loan payment

  If paying electronically, pay PAYE, class 1 NICs, student loan deductions and deductions from payments to subcontractors for the month up to the 5th of this month.

31 March 2021

• Corporation tax

  End of corporation tax financial year.

• CT61

  End of CT61 quarterly period.

• Corporation tax return

  Filing deadline for corporation tax return self-assessment form CT600 for period ended 31 March 2020 to be submitted to HMRC.

• Company accounts filing deadline

  Deadline for filing your company tax return is 12 months after your accounting period for corporation tax ends.