CRA review letter: reply by its deadline, with the reference number

Which CRA review sent the letter, and what comes next?

The CRA runs eight review programs on T1 returns, and the program decides whether the letter arrives before or after the notice of assessment canada.ca. The CRA says being selected for review does not represent a tax audit canada.ca. If an auditor is involved, the CRA audit process applies instead.

For the Preassessment Review, Processing Review, Request Verification and Matching programs, the CRA first tries to verify the claim with information it already has, and contacts your client or you by phone or in writing only when it needs more canada.ca. A return selected for review can take longer than the 4 weeks the CRA aims for on 95% of EFILE returns canada.ca. A Request Verification letter means the CRA is checking a change you asked for, which ties it to Change my return.

How do you answer the letter before its deadline?

The CRA doesn't publish one standard deadline for review letters. Each letter states its own time frame, and that date is the one that counts canada.ca.

The steps follow the CRA's page on responding to a review canada.ca. In Submit documents, a case or reference number is needed when the CRA has asked for documents. Each file needs a unique name, most programs accept up to 500 MB per submission, and the upload shows in the history table within 24 hours canada.ca. If you get a "Service Unavailable" error, the CRA says the file is usually corrupted or unsupported, so save it as a PDF and try again.

Your access level matters. In Represent a Client, Submit documents needs Level 2 authorization (Level 1 has no access), while the client's mail is viewable at every level canada.ca. With Level 1 you can read the letter but your client has to upload, or you mail the package to the address on the letter.

What proof does the reviewer expect for the claims it checks most?

The CRA publishes the claims it most often adjusts on review and the documents it usually wants for each canada.ca. Send the full set with the first reply.

Two details catch people. For US tax, an IRS Tax Return Transcript alone is not enough; the CRA wants the account transcript. And documents in another language need the original plus an acceptable English or French translation, done by someone other than the taxpayer canada.ca. Medical receipts for over the counter products such as vitamins are refused regardless of the paperwork; the medical expense threshold page covers what counts.

What happens if your client misses the deadline?

If the requested information doesn't arrive by the date in the letter, the CRA reviews the claim with what it has and may reduce or deny it, which can leave a balance owing canada.ca. Late is still better than never: when a claim has been changed and your client then finds the documents, the CRA accepts them and reviews the claim again for a possible adjustment canada.ca.

The formal route only opens once a notice exists. Under ITA 165(1), a taxpayer objects to an assessment, and an individual has until the later of one year after the filing due date and 90 days after the notice was sent; corporations get 90 days laws-lois.justice.gc.ca. The CRA suggests calling or writing to discuss the disagreement first, since many disputes end there canada.ca.

Interest generally still runs on the amount in dispute, and paying all or part of it reduces the interest. Once an objection is filed, the CRA normally postpones collecting the disputed income tax until 90 days after it sends its decision canada.ca. The rate is on the CRA overdue interest page, and the full objection rules are on the notice of objection deadline page.

When does each deadline fall in a 2025 medical expense review?

Your client is an employee who filed a 2025 T1 by April 30, 2026 and claimed medical expenses. A Processing Review letter dated October 15, 2026 asks for the receipts by the date printed on it, say November 16, 2026. Your client finds everything except $2,000 of receipts, and the claim that remains still clears the threshold.

The lost receipts cost a federal credit of $2,000 × 14.5% = $290, because 14.5% is the blended lowest federal rate for 2025 canada.ca. The provincial credit on the same $2,000 goes too, plus interest.

If your client or their spouse is a sole proprietor, the 2025 filing due date was June 15, 2026 canada.ca, so the last day to object moves to June 15, 2027. Use the months before that date to find the receipts and send them in as new information, which can settle the matter without an objection.

Why did the letter go to your client instead of you?

The Special Assessments Program sends its information requests straight to your client, not to you as the preparer canada.ca. So ask clients to forward any CRA letter, and check their mail in Represent a Client yourself.

Selection itself says little about the return. The CRA picks returns when they don't match third party slips such as T4s, by the type of deduction or credit claimed, by compliance history, or at random, and every return passes through its computer screening canada.ca. The CRA says a selection doesn't reflect on you as the preparer canada.ca.

The CRA may ask for more than receipts, such as cancelled cheques or bank statements, and tells individuals to keep supporting documents for at least six years canada.ca. ITA 230(4) sets the same six years from the end of the last tax year the records relate to laws-lois.justice.gc.ca; the exceptions are on the record retention page.