What if I miss the 90-day deadline to object to a CRA assessment in Canada?

This answer covers Canadian federal tax law, which applies in every province.

Missing the objection deadline does not always end your options, but the time to ask for more is limited. If no objection was made in time, you can apply to the Minister for an extension, giving the reasons for the delay and addressing it to the Chief of Appeals with a copy of the notice of objection.

The application must be made within one year after the objection deadline expired, and you must show you were unable to act or had a bona fide intention to object, that granting it is just and equitable, and that you applied as soon as circumstances permitted. If more than one year has passed, no extension can be granted.

If the Minister refuses, or 90 days pass without a decision, you may apply to the Tax Court of Canada within 90 days after the decision notice was mailed. Your deadline also depends on your situation, since individuals generally get the later of one year after the filing due date and 90 days after the notice was sent. Objections filed late may be invalid.