If you disagree with your tax assessment or re-assessment from the Canada Revenue Agency, you can appeal the assessment by filing a Notice of Objection within 90 days from the date that CRA sends you the Notice of Assessment (usually the date stated at the top of the Notice of Assessment). But it often takes months for your appeal to even get assigned to an Appeals Officer and sometimes years for the CRA Appeals Division to make a final determination on your appeal. In the meantime, CRA is charging you interest, compounded daily, on the assessed amount. The interest can result in doubling or tripling the debt if your appeal is unsuccessful. The interest rate is determined every three months and the prescribed rate is published on the CRA website. The current prescribed annual interest rate is 6%.
If you want to speed up your appeal, you can apply directly to the Tax Court of Canada to have the Court deal with it if the CRA Appeals Division has not decided on your appeal within 90 days from filing your income tax objection, or 180 days from filing your GST / HST objection. Once your appeal is filed in the Tax Court, it will still take a while to get a hearing date to finally resolve your dispute, but at least there are time limits set out in the Tax Court Rules for the Government to file its Reply, if any, and after that, the Court will make an Order setting out a timetable for the completion of the remaining steps in the case, and for a hearing date.