CRA Interest % on overpayment after review? and when it kicks in?

Tax Topics
1

-What is the CRA Interest rate Now on June 2025 after the client has been found to owe money to CRA after review? is it 5%?

-When does the clock start on Interest? On the day the client was paid the refund, or after they found he/she owes money?

-What’s the process to ask for waiving the interest for the client?

2

See applicable interest rates here:

CRA generally starts charging interest a month after the payment was due. So, for example, a 2024 personal tax balance that was due April 30, 2025 will start to accrue interest May 1, but generally won’t be APPLIED to the balance until June 1. See here:

The process to ask for interest to be waived is called “Taxpayer relief”. You have to fill out and send them a RC-4288: