- 14 March 2018 (23rd March 2018 for online payment and filing):
P30 Monthly Return and payment for February 2018
- 19 March 2018 (23rd March 2018 for online payment and filing):
Bi-monthly VAT 3 Return and payment for the period January/February 2018
- 21 March 2018 (23rd March 2018 for online payment and filing):
Corporation Tax Return CT 1 and final payment for companies with accounting periods ending 30 June 2017
- 21 March 2018 (23rd March 2018 for online payment and filing):
Preliminary Corporation Tax due (where liability is less than €200,000) for accounting periods ending 30 April 2018
- 21 March 2018:
Form 46G for companies with accounting periods ending 30 June 2017