Tax Return Filing Date. The deadline for your tax return is 12 months after the end of the accounting period it covers. You’ll have to pay a penalty for late filing if you miss the deadline.

Fiscal year corporate taxpayers must file their tax returns by the 15th day of the fourth month following the end of their tax year. If a due date falls on a weekend or public holiday, we can receive your return and payment on the next working day without a penalty being applied.