The short version
Match the notice to the right year, then read the summary together with any explanation of changes.
The Canada Revenue Agency describes a notice of assessment as a summary of the calculated amounts for an income tax and benefit return. A notice of reassessment updates an assessed return after changes. This guide helps locate information on those documents. It does not determine whether an amount is correct or advise you how to file, object or make a payment.
Check which notice and year you are reading
Locate the tax year and issue date before comparing numbers. If you have more than one notice, keep them distinct; a later document may not refer to the year you first assumed. Access your CRA account through its official sign-in route when you need the full current record.
Protect identifiers and access codes. A request to explain a heading usually does not need your full tax document. Do not paste a NETFILE access code, SIN or account credentials into a public discussion or an unnecessary upload.
Read the summary and changes together
The CRA’s guide distinguishes an account summary from the tax assessment or reassessment summary and an explanation of changes. Find each section rather than treating the most prominent number as the whole explanation.
Compare the relevant line descriptions with your own records privately. Note where you need clarification without asking AI to invent missing amounts. The official guide explains that timing can matter—for example, a payment may not yet appear on a notice issued earlier. Confirm current information directly rather than assuming a payment was lost.
Prepare precise questions for the CRA or your adviser
Record the notice year, section heading and line you do not understand. Ask which document or explanation supports a change and where to find the current account information. Keep a record of the response without including sensitive numbers in a shared calendar note.
A question about disagreeing with an assessment, changing a return or a dispute deadline needs the relevant official process and, where appropriate, qualified tax advice. Do not treat the reading checklist or an AI summary as an objection, a filed return or a request for an extension.
Fictional reading example
A fictional reader sees a different amount in an assessment summary than in their saved return. They locate the explanation-of-changes section and prepare a question about the named line. The example does not conclude that the CRA or the reader made an error.
Your checklist
- Identify NOA or reassessment and tax year
- Locate notice date and account summary
- Read any explanation of changes
- Keep tax identifiers and access codes private
- Use official help for correction or dispute questions
Sources & limitations
This page explains document organization, not tax calculations, entitlements, filing choices or dispute deadlines.
These official sources support the reading guidance; they do not endorse Paperwork Wingman. Check the issuer’s current instructions for your situation.
- Canada Revenue Agency — Notices of assessment and reassessment (opens in a new tab)
- Office of the Privacy Commissioner of Canada — 10 tips for protecting personal information (opens in a new tab)