My CRA assessment is different from what I filed — what should I do?
It is common for CRA's Notice of Assessment to differ from your filed return. Sometimes the difference is minor — CRA may have a T4 or T5 slip on file that you did not include, or it may have adjusted RRSP contribution room based on its records. Review the notice carefully and compare it line by line against your return to understand what changed.
If the difference is the result of CRA adding a slip you missed, you may owe the additional tax and should pay it to stop interest from growing. If you believe CRA's adjustment is wrong — for example, you have a deduction it denied or a credit it missed — you have options. For minor corrections, you can request an adjustment through My Account (online) or by filing a T1 Adjustment Request. For more significant disputes, or if CRA has denied something substantive, filing a formal Notice of Objection is the appropriate path.
The 90-day objection deadline from the date on the Notice of Assessment (or Reassessment) is strict. If you miss it you can apply for an extension for up to one additional year, but this is not guaranteed. Act promptly and consult a professional if the amount is meaningful.
Key takeaways
- Review the notice line by line to understand what CRA changed and why.
- Minor discrepancies (missing slips) can often be addressed by paying the balance or filing a T1 adjustment.
- For substantive disputes, file a formal Notice of Objection within 90 days.
- The 90-day deadline is firm; missing it requires a separate extension application.