Faxing the tax authority
A review letter, a reassessment, a request for receipts: your SIN and the letter’s reference do the sorting.
In Canada, federal income tax — and provincial personal income tax everywhere except Quebec — is administered by the Canada Revenue Agency. The CRA prefers documents submitted online through My Account or Represent a Client, but a number of its letters and forms still print a fax number for the reply. Use only the number printed on the letter you are answering, since each program and centre has its own. Put your social insurance number or business number and the letter’s reference on the cover page, and read the notice itself for the deadline and accepted channels before filing a formal objection.
Why the tax authority still takes faxes
Reviews and verifications at the CRA are run by programs that exchange documents with taxpayers, accountants and employers. Fax has remained one of the accepted ways to send receipts back, and several letters and forms still list a dedicated number for that purpose.
For you, a dated transmission report shows when your documents left — useful when a letter gives you a set number of days to respond before the agency adjusts your return. If the letter offers no fax number, use the online upload rather than hunting for one elsewhere.
Where to find the right number
- The letter you received: review letters and requests for information state the reply options, sometimes including a fax number specific to that program.
- The form itself: some CRA forms explain where to send them, by mail or fax, depending on where you live.
- The CRA’s individual or business enquiries line, to confirm that a fax will reach the program handling your file.
What the cover page should say
- The CRA program or centre named on your letter.
- Your social insurance number or business number, and the reference or case number shown on the letter.
- The tax year concerned and the subject: reply to a review, supporting receipts, signed form.
- A list of the enclosed documents and the total page count.
The record to keep
Keep the transmission report, the exact PDF and the CRA letter it answers together. If a reassessment arrives saying no documents were received, those three show what went out, when and to which number. The FaxTelecom PDF receipts option adds a dated record of the transmission, charged only if delivery succeeds.
Other channels, sometimes better
My Account and Submit documents
Uploading through My Account links documents directly to your file and shows them in your history. It is the route the CRA prefers.
Represent a Client
If an accountant handles your taxes, they can upload documents on your behalf through the CRA’s representative portal.
A formal objection online or by mail
An objection to an assessment can be filed online or on Form T400A by mail; the deadline is set out on your notice.
Other recipients
- After a leak, a crash or a burglary, the clock on reporting starts ticking: proof of sending counts.
- Sick note, certificate, proof of absence: let them know on time without saying too much.
- An application, proof of age, a direct-deposit change: one wrong SIN and the file stalls.
- Health data on paper again: the number must come from the plan, not from a search engine.
Faxing a public body
In this section
Where to go next
Hand-picked pages to help you prepare, send or prove your fax.