If you disagree with an income tax assessment you have 90 days to file a Notice of Objection. If you miss that deadline you have no further rights to appeal without the consent of the Canada Revenue Agency.
"This article provides information of a general nature only. It is only current at the posting date. It is not updated and it may no longer be current. It does not provide legal advice nor can it or should it be relied upon. All tax situations are specific to their facts and will differ from the situations in the articles. If you have specific legal questions you should consult a lawyer."