What to do next
Diarise the deadline from the notice the day it arrives
The period runs from the date on the notice of assessment, not from when you opened it. Extensions exist but must themselves be applied for within a further limited window.
File the objection with reasons and facts
State the facts, the issues, and why the assessment is wrong. Attach supporting documents. A bare disagreement without reasons wastes the stage that is cheapest to win at.
Check whether Quebec requires a parallel objection
Quebec collects its own personal income tax, so one issue can produce both a CRA and a Revenu Québec assessment. Objecting to one does not preserve your rights against the other.
Appeal to the right court if the objection fails
Federal assessments go to the Tax Court of Canada — informal procedure for smaller amounts, general procedure above the threshold. Quebec assessments generally go to the Cour du Québec.
Frequently asked questions
What if I missed the objection deadline?
You may be able to apply for an extension, but that application also has a deadline and requires explanation. Act immediately — this is the most commonly fatal error in tax disputes.
Do I need a lawyer or an accountant?
Accountants handle many objections well. Legal advice matters more where facts are contested, penalties are alleged, or the matter is heading to court.
Is the informal procedure cheaper?
Yes — simplified rules, relaxed evidence, lower cost, available under a defined amount. Above that threshold the general procedure applies.
Do I have to pay while disputing?
It depends on the type of tax. Interest continues to accrue, so ask about paying under protest to stop the interest while preserving the dispute.
This is general information, not legal advice. Laws vary by location and every situation is different — speak with a qualified lawyer about your specific circumstances.