You must file a return no later than three years after the end of a tax year to receive a tax refund.
Penalties
What happens if you file your return late?
If you file your return late, a penalty applies. The penalty is 5% of the unpaid tax that is due on the filing deadline, plus 1% of this unpaid tax for each complete month that the return is late, up to a maximum of 12 months.
The corporation will be charged an even larger penalty if we issued a demand to file the return under subsection 150(2), and if we assessed a failure to file penalty for the corporation in any of the three previous tax years. The penalty is 10% of the unpaid tax when the return was due, plus 2% of this unpaid tax for each complete month that the return is late, up to a maximum of 20 months.