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Figures: 2026 tax year

Changing a return you already posted

What to do when you spot a mistake after posting a T1: how to request a change through the CRA, what Form T1-ADJ is for, and when to leave a small error alone.

Updated 24 July 2026 · 1 min read

Post a return and find a mistake a week later. This happens often, and the CRA has a process for it.

Wait for the first return to be processed

Do not post a corrected copy of the same return. Two returns for the same year confuse the system and slow both. Wait until the CRA has processed the first one, then amend it.

Ask the CRA for a change

Do not file a second T1. Wait for your notice of assessment, then request a change through CRA My Account, or by post using Form T1-ADJ. You may request a change for the current year and the previous ten.

Hypertax does not prepare a T1-ADJ.

When to leave it

If the CRA's own review will catch and correct it, an amendment may be unnecessary. A missing slip is usually matched automatically and you receive a reassessment. A wrong bank account or a missing credit needs you to act.

If the mistake came from a bad slip

Get the corrected slip first, then amend. Read your T4 is wrong.

Sources

Every figure and every procedure on this page was checked against the pages below on the date shown. The agencies revise these pages, so confirm anything you are about to act on.

  1. How to change your return (opens in a new tab)canada.ca · checked 24 July 2026
  2. Understand your notice of assessment (opens in a new tab)canada.ca · checked 24 July 2026

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This article explains a form and a process. It is general information, not tax advice about your own situation, and Hypertax does not send your return to the CRA — you print it and mail it. See the not-tax-advice notice and the rest of the help centre.