- 21 August 2021 (23rd August 2021 for online payment and filing):
Corporation Tax Return CT 1 and final payment for companies with accounting periods ending 30 November 2020
- 21 August 2021 (23rd August 2021 for online payment and filing):
Preliminary Corporation Tax due (where liability is less than €200,000) for accounting periods ending 30 September 2021
- 21 August 2021:
Form 46G for companies with accounting periods ending 30 November 2020
