Understanding interest

We will charge interest if you make late or insufficient payments. This interest is called instalment interest or arrears interest, depending on the debt. We pay applicable refund interest up to the day an overpayment is refunded, repaid or applied.

The interest rate is determined every three months in accordance with the prescribed interest rate compounded daily.

The interest rate on underpayments is based on the average rate of three-month treasury bills sold during the first month of the previous quarter rounded to the next higher whole percentage point and raised 4 percentage points.

The interest rate on overpayments is based on the average rate of three-month treasury bills sold during the first month of the previous quarter rounded to the next higher whole percentage point.

You can request an interest review or a Statement of Interest using "Make online requests" service at:

• Represent a Client, if you are an authorized representative or employee; or
• My Business Account, if you are the business owner.

You can also view previously-issued statements using the "View correspondence" service at:

• Represent a Client, if you are an authorized representative or employee; or
• My Business Account, if you are the business owner.

Forms and publications

• Corporation Instalment Guide (T7B-CORP)