CRA pre-assessment review: why your refund is on hold

What happens in a CRA pre-assessment review

In a CRA pre-assessment review, the CRA stops your return before assessment and asks you to support one or more amounts. Nothing is assessed, so there is no notice of assessment, no refund and no updated benefit calculation until the reviewer is satisfied or makes a decision.

This is different from a return that is simply slow: a review always comes with a letter asking for documents, by mail or in My Account. If there is no letter, see our CRA refund delay page for the other common causes.

Why returns are selected before assessment

The CRA says it selects returns for review when amounts do not match information from third parties, because of the kinds of deductions or credits claimed, because of compliance history, or at random. Pre-assessment reviews focus on income, deductions and credits the CRA wants to confirm before it pays anything out.

Claims that rely on receipts the CRA never sees at filing time are natural candidates, since an electronic return carries only the totals. Think of medical expenses, child care, moving costs, support payments, tuition amounts and donations. A first-time claim or an amount much larger than in past years can also stand out.

CRA pre-assessment review vs processing review

People often mix up the two because the letters look alike. The timing is the difference, and it changes what is at stake.

In a pre-assessment review the worst outcome is usually a smaller refund than you expected. A processing review happens after the refund may already be in your bank, so a denied claim can turn into a CRA balance owing that you have to repay with interest.

How to respond quickly

The review cannot move until the CRA has what it asked for, so the calendar is largely in your hands. Aim to reply within days, not at the deadline.

1. Read the letter closely and list every item requested, including which tax year and which line.
2. Collect documents for the full amount claimed, not just part of it. A $1,450 child care claim needs receipts adding up to $1,450.
3. Upload through Submit documents in My Account using the reference number from the letter, or mail copies to the address it gives.
4. If something is lost, write a short explanation and include what you do have, such as bank statements showing the payments.
5. Keep the confirmation number and check My Account mail rather than resending the same files.

The full upload rules, file limits and what to do if you need more time are on our CRA review letter page.

Calling about a pre-assessment review letter

Use the phone number at the bottom of your letter. The CRA lists Monday to Friday, 8 am to 5 pm Eastern time for pre-assessment review enquiries, and a TTY line at 1-800-959-7386. If you need more time to gather documents, call that number before the reply date in the letter rather than letting it pass.

How long does a CRA pre-assessment review take?

There is no published CRA pre-assessment review processing time. The CRA's processing-times page (95% of e-filed returns within 4 weeks and paper returns within 8 weeks) and its 2026-27 service standards (2 weeks for digital returns, 12 weeks for paper) both exclude cases where it has to contact you for more information. Your review therefore runs on its own clock.

What you can control is the gap between the letter and your reply. A complete upload the same week the letter arrives removes most of the waiting that is in your hands. A partial reply often means a second letter and another wait.

Does the CRA pay interest while it holds your refund?

Sometimes. The CRA pays compound daily interest on a refund from the latest of three dates: 30 days after the balance-due date, 30 days after you filed, or the day you overpaid. For an employee whose 2025 tax was withheld at source and who filed on 10 March 2026, the latest of those dates is generally 30 May 2026, 30 days after the April 30 balance-due date, so a review that runs into the summer can earn some interest. The non-corporate overpayment rate is 5% for October to December 2026.

After the review

When the reviewer finishes, the CRA issues your notice of assessment. If every claim was supported, it matches your return and the refund follows. If a claim was reduced, the notice explains the change and the refund is smaller, or you may owe.

You can still send new documents after the assessment, and the CRA says it will look at the claim again. If you think the decision is wrong in law rather than missing proof, a formal objection is the route. See the after you file guide for how each of these steps connects.

Does the year-round review schedule affect pre-assessment reviews?

The CRA's move to year-round reviewing, effective April 2026, applies to post-assessment reviews, which happen after your notice of assessment has been issued. A pre-assessment review still happens before the assessment, so it is still tied to when you filed.

What this means in practice is that being cleared at the pre-assessment stage no longer implies the file is closed for the season. A post-assessment review of the same return can follow later in the year.