CRA Form T1-ADJ T1 Adjustment Request
Request changes to a personal income tax return you have already filed with the CRA.
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About T1-ADJ
Form T1-ADJ, T1 Adjustment Request, is used to ask the Canada Revenue Agency to change one or more amounts on a personal income tax return you have already filed and had assessed. It is the paper option for correcting a previously filed return.
You can use the form to add missed deductions or credits, correct income amounts, or fix other errors and omissions. For each change, you identify the line involved, the amount as filed, and the corrected amount, along with an explanation.
Many taxpayers can also make adjustments online through CRA services, but the T1-ADJ remains available when you prefer to file on paper or need to include supporting documents by mail.
Who needs to complete it
- Taxpayers who forgot to claim a deduction or credit on a filed return
- Individuals who need to correct income reported on a previous return
- People who received a slip after filing their return
- Anyone who discovered an error or omission on an assessed return
- Taxpayers who prefer to request changes by mail rather than online
How to fill out T1-ADJ
- 1Enter your identification details, including your name, address, and social insurance number.
- 2Indicate the tax year of the return you want to adjust.
- 3For each change, enter the line number affected on the return.
- 4Enter the amount as previously reported and the corrected amount.
- 5Explain the reason for each change clearly.
- 6Attach any supporting documents that back up the requested changes.
- 7Sign and date the form and mail it to your tax centre.
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Frequently asked questions
When should I use a T1-ADJ?
Use it after your return has been assessed and you need to change amounts, such as adding a missed credit or correcting income.
Can I adjust more than one year?
You generally submit a separate request for each tax year you want to change.
How far back can I request a change?
There are time limits on adjustments. Requesting changes for older years may require additional steps, so submit as soon as you identify the error.
Do I need to attach documents?
Include any supporting documents, such as slips or receipts, that support the changes you are requesting.