CRA Refile Error 603 – Change Cannot Be Processed

Error Message

When refiling your return, the CRA may return the following error:

603: The change you are trying to make cannot be processed through the ReFILE service.

What This Means

This error can occur for two reasons:

1. The original return has not yet been assessed by CRA. An amendment cannot be submitted until the initial return has been fully assessed. In this case, simply wait until you receive your Notice of Assessment (NOA), then try refiling again.
2. The CRA ReFILE system cannot handle the type of change you are trying to make. Not every adjustment is eligible for ReFILE — certain changes must be submitted through a different channel.

How to Fix It

If the original return has not been assessed yet, wait for CRA to process it and issue your Notice of Assessment. Once assessed, you can retry the ReFILE.

If the change itself is not supported by ReFILE, you have two options:

Option 1 — Use your CRA My Account

Sign in to your CRA My Account and submit the change directly through the Change my return service.

Option 2 — File a T1 Adjustment (T1-ADJ)

If you prefer to submit the change on paper, you can file a T1 Adjustment Request (T1-ADJ):

1. Add the T1-ADJ form to your return using the Add/Remove Forms tool.
2. Fill in the T1-ADJ form with the details of the change you want to make.
3. Print the completed T1-ADJ.
4. Mail the printed form to the CRA at the address indicated on the form.

Note: The T1-ADJ cannot be transmitted electronically from StudioTax — it must be printed and mailed to CRA.