CRA review letter: what it means and how to answer it

What is a CRA review letter?

A CRA review letter is a request for proof. The CRA assesses most returns by computer first so notices go out quickly, and can check selected claims later against receipts or slips from employers and financial institutions. The letter names the tax year, the line or claim being checked, the documents it wants and a date to reply.

Returns are picked for several reasons, according to the CRA: amounts that do not match slips from employers and banks, the type of deduction or credit claimed, your past compliance history, and pure random selection. Getting a letter does not mean the CRA thinks you did something wrong.

CRA review letter vs audit

A review is narrow. It focuses on one or a few specific amounts, is handled by correspondence, and usually ends once you send the requested documents. The CRA's review page states plainly that a review does not represent a tax audit. Audits are a separate and much deeper examination with their own process.

In practice, the difference shows in the scope of what is asked. A review letter might want medical receipts totalling the $3,100 you claimed on line 33099. An audit looks at books and records across the whole return or business. If a review letter asks only for receipts for one claim, you are dealing with a review.

Types of CRA reviews

The CRA runs eight review programs for individual returns. The name of the program, or the timing of the letter, tells you whether your notice of assessment is on hold or whether a reassessment could follow.

Matching and Supplementary Examination letters

A Matching letter comes after your notice of assessment: the CRA has compared your return with information from third parties such as employers and financial institutions, for example when a slip issued in your name does not match what you reported. For questions about a T1 Matching letter the CRA lists 1-866-772-2237, and 1-800-263-4747 for its Pre-Matching program. A Supplementary Examination contact letter concerns income or loss amounts, or deductions, that need a more detailed examination, and can arrive before or after a notice of assessment or reassessment. Both are still reviews: reply with the reference number and the documents listed, the same way as any other review letter.

A letter that arrives before your notice of assessment is covered in detail on our CRA pre-assessment review page, because it freezes the refund until you reply.

How to respond to a CRA review letter, step by step

A complete first reply is the single biggest factor in how fast a review closes. Send everything the letter lists at once rather than in pieces.

1. Find the reference or case number in the upper right corner of the letter and note the reply date.
2. Gather every document listed. For a missing receipt, write a short explanation and include other proof, such as a bank statement or cancelled cheque.
3. Scan each document at 200 dpi or lower, as PDF or JPG where possible.
4. Sign in to My Account (or Represent a Client, for an authorized representative) and select Submit documents.
5. Enter the tax year and the case or reference number with no spaces, so the files reach the right program.
6. Upload up to 10 files in one session, giving each file a unique name (the CRA suggests including the line number), then confirm.
7. Save the confirmation number with a copy of what you sent.

Worked example: a medical expense review

Say the letter asks you to support $3,100 of medical expenses on line 33099 of your 2025 return. You have pharmacy printouts for $1,900, a dental receipt for $800, and a physiotherapy clinic that has closed, so the last $400 has no receipt. Upload the two sets of receipts, add your credit card statements showing the three physiotherapy payments, and include a one-paragraph note explaining that the clinic closed and naming the dates and amounts.

That reply gives the reviewer everything in one pass. If the CRA accepts only the $2,700 backed by receipts, the change to your credit is modest: with 2025 net income of $50,000 the 3% threshold is $1,500, so the claim drops from $1,600 to $1,200 and the federal credit falls by $58 at the 14.5% rate. Knowing the stakes helps you decide how much effort a missing receipt deserves.

Writing a reply letter to the CRA

A short cover letter helps the reviewer match your documents to the file. Put the reference number from the upper right corner of the CRA's letter at the top, then your name, the tax year and the claim being reviewed, followed by a numbered list of what you enclosed. Where a receipt is missing, explain why in a sentence or two and point to the other proof you included. Keep it factual: there is no need to argue the law at this stage.

Replying by mail

You can mail copies to the address printed in the letter instead. Put the reference number on every page and keep the originals. Mail is slower and gives you no instant confirmation, so upload online if you can.

File formats the upload accepts

The CRA's online portal accepts .pdf, .doc, .docx, .xls, .xlsx, .rtf, .txt, .jpg, .jpeg, .tif, .tiff and .xps files, up to 150 MB per submission. A representative needs level 2 authorization to upload for a client.

CRA review letter deadline and extensions

There is no single deadline for every review. The reply date is set in your letter, and that is the date that counts. If you cannot meet it, for example because a clinic needs time to reprint receipts, call the number at the bottom of your letter before the date passes and ask for more time.

If the date passes with no reply, the CRA can finish the review with what it has. For a claim it cannot verify, that usually means reducing or denying the claim and issuing a notice of reassessment. On a $3,100 medical claim, losing the credit could mean a new CRA balance owing with interest.

After you respond: processing time and outcomes

The CRA does not publish a single processing time for reviews. Its service standards for returns exclude cases where it has to contact you for more information, so the clock depends on the program, the season and how complete your reply was. Watch the progress tracker and your My Account mail rather than sending the same documents twice.

• Claim accepted: the file closes. If the review happened before assessment, your notice of assessment follows.
• Claim changed: you receive a notice of reassessment explaining the change, with any refund or balance.
• New documents later: the CRA says it accepts new submissions after a claim is changed and will look at it again.

If you disagree with the result

Start by sending any extra proof you have. If the CRA still refuses and you believe it applied the law incorrectly, you can file a formal objection, generally within 90 days of the date on the notice. The steps are on our notice of reassessment page, and the whole post-filing sequence is mapped in the after you file guide.

CRA reviews now run year-round

Review letters used to arrive in seasonal waves, mostly in the months after the filing deadline. That changed in 2026: the CRA said that effective April 2026 it would conduct post-assessment reviews of individual income tax and benefit returns on a year-round basis.

The practical effect is that a letter in October about a return filed in April is now ordinary rather than unusual. It does not mean your return was singled out, and it does not change what the letter asks for or how long you have to answer.