- 14 JuneApril 2018 (23rd June 2018 for online payment and filing):
P30 Monthly Return and payment for May 2018
- 21 June 2018 (23rd June 2018 for online payment and filing):
Corporation Tax Return CT 1 and final payment for companies with accounting periods ending 30th September 2017
- 21 June 2018 (23rd June 2018 for online payment and filing):
Preliminary Corporation Tax due (where liability is less than €200,000) for accounting periods ending 31st July 2018
- 21 June 2018:
Form 46G for companies with accounting periods ending 30 September 2017