- 14 December 2018 (23rd December 2018 for online payment and filing):
P30 Monthly Return and payment for November 2018
- 21 December 2018 (23rd December 2018 for online payment and filing):
Corporation Tax Return CT 1 and final payment for companies with accounting periods ending 31 March 2018
- 21 December 2018 (23rd December 2018 for online payment and filing):
Preliminary Corporation Tax due (where liability is less than €200,000) for accounting periods ending 31 January 2019
- 21 December 2018:
Form 46G for companies with accounting periods ending 31 March 2018