Compare it with the filed return
Check the taxpayer, tax year and reported result against the copy of the return. Read the explanation of changes instead of looking only at the refund or balance owing. Some differences are straightforward; others need supporting records or a discussion with the preparer.
Keep the notice together with the filed return and relevant correspondence. That makes it easier to understand the sequence if the CRA later issues a reassessment or asks for additional information.
Treat the document as sensitive
An assessment contains personal or business tax information. Obtain it through an appropriate channel and share it securely when your accountant needs it. A general website enquiry is not the place to paste tax identifiers or upload the document without confirming the process.
A message asking you to act should also be checked for authenticity. Use established CRA sign-in and contact channels when verifying an unexpected request.
An unexpected change needs a next step
If the result differs from what you expected, identify the specific change and gather the evidence behind it. Correcting a return, responding to a review and formally disputing an assessment are different processes with different requirements.
Do not let an unresolved question sit simply because a payment or refund has already moved. Ask promptly which process applies and confirm any deadline from the actual notice and current guidance.
Sources & editorial notes
Sources checked October 23, 2026. The examples are illustrative and provide general information. Discuss how the guidance applies to your circumstances with your accountant.
- After sending your tax return: reading a notice of assessmentCanada Revenue Agency
- Where and how long to keep recordsCanada Revenue Agency
Rules and guidance can change. Use the current official source and confirm the treatment for your facts. To flag an error, contact Sora.