What does it mean if the CRA reassesses my tax return?

A CRA reassessment means the CRA has reviewed your original tax return and made changes to it — either increasing or decreasing the tax you owe. You will receive a Notice of Reassessment (NoR) by mail or through My Account, showing the adjusted amounts. Reassessments can happen for various reasons: a routine review, information from a third party (like an employer or financial institution), matching of slips reported versus claimed, or a more detailed audit.

If the reassessment results in more tax owing, it also includes any applicable interest and potentially penalties. If it results in a refund, the CRA will pay that to you. The reassessment does not mean you have done anything wrong — many are corrections of errors the CRA itself identified or adjustments based on information that differed from what you reported.

You have the right to object to a reassessment you disagree with. If you are an individual (other than a trust) or a graduated rate estate, you must file a Notice of Objection by the later of one year after the return's filing-due date and 90 days after the mailing date of the Notice of Reassessment; other taxpayers, including corporations, must object within 90 days of that date. If you miss this deadline, you can apply to the Minister (CRA) for an extension of time to object, within one year after the deadline — and only if that request is refused can you then apply to the Tax Court of Canada. Do not ignore a Notice of Reassessment — even if you think it is wrong, responding within the window is essential. A tax lawyer or accountant can help you decide whether to object and how to build your case.