Keep the document sequence visible
Federal pay guidance says amended and cancelled slips carry status and issue-date information. Retain those details alongside the original record. If several documents exist, establish which replaces which before relying on an amount.
An adjustment can affect more than employment income. Compare all changed boxes, relevant Québec documents and the issuer’s explanation. If the source information is unclear, obtain clarification through the appropriate pay or pension channel rather than deciding that the smallest income amount must be correct.
Worked example: two changed boxes
Imagine a hypothetical Ottawa employee whose original 2025 slip shows $92,400 of employment income and $18,900 of income tax deducted. A replacement shows $90,600 and $18,450 respectively. Employment income decreased by $1,800, while withholding decreased by $450.
The return review must account for both changes and any other affected information. The $1,800 difference does not equal a $1,800 refund, and the withholding change matters to the balance. The final tax effect depends on the complete return.
Use the process that matches filing status
If the return has not been filed, use the applicable current information in preparing it. Federal pay guidance also advises meeting the filing deadline using available slips when an expected amendment has not arrived in time. Waiting for a possible change does not automatically extend the deadline.
For a filed return, CRA requires assessment before a change request. Review the return, notice and revised slip, then use an eligible correction method with the required authorization. Keep a pending request visible so a second overlapping submission is not sent without review.
Follow the change through to the result
Save the proposed line changes, supporting documents and submission confirmation. Compare the reassessment with the requested correction when it arrives, including the resulting payment or refund and any remaining explanation. A replacement slip alone does not prove that the assessed return has been changed.
If the slip concerns an older year, check the applicable adjustment limits promptly rather than copying a date from an old checklist. Formal disputes or complex overpayment questions require a separately confirmed review. The goal is a supported correction to the right year with a traceable result.
Put this into practice
Sources and current guidance
A practical next step
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