6If you have a tax refund owing to you, there are certain timelines used to calculate the refund interest you may receive.
The Canada Revenue Agency pays refund interest to taxpayers on the latest of the following dates: a) the date of the actual overpayment; b) the 120th day after the end of the tax year, if the return for the year was filed on time; or, c) the 30th day after the date the return was filed, if it was filed late.