Last updated · Written for a business outside North America with a US or Canadian agency form to file. We are not affiliated with any government agency and nothing here is tax, legal or immigration advice.
You do not need a US or Canadian phone line to fax a US or Canadian number — you need a service that will place the call for you. An online fax service dials the destination from its own network, so from abroad the whole job is a file upload in a browser. The part people get wrong is the other direction: any reply travels back to the number that placed the call, so if an agency will fax you something, you need a number of your own.
Why a business outside the US ends up faxing a US agency
Because the agency’s intake desk has not changed since the 1990s, and because the alternative is slower. A newly formed company with no US residence, a foreign contractor delivering work in Canada, a European firm resolving a US tax account — all of them hit a form whose instructions name a fax number and a mailing address, and international post against a filing deadline is not a plan.
The pattern we see is narrow and consistent: one document, one deadline, one institutional recipient. Not a fax habit, an errand. Our own pages on faxing Social Security and faxing the CRA cover the two agencies this comes up with most, and the Regulation 105 waiver is a filing that only a non-resident ever makes.
How to write a US or Canadian fax number from abroad
The United States and Canada share the North American Numbering Plan: country code 1, a three-digit area code, then a seven-digit local number. A Canadian fax number is therefore indistinguishable in form from a US one. With an online fax service you do not dial your country’s exit code — no 00, no 011 — you enter the number with its country code and the service handles the call.
| Your situation | What you need | What it costs on usfax.com |
|---|---|---|
| One document out, no reply expected by fax | A way to send. No number of your own. | Pay Per Fax, $2.99 for up to 10 pages, no subscription. |
| The agency may fax something back | Your own dedicated fax number, because the reply goes to the sending number. | Solo, $19 a month ($15 billed annually), one number, 300 pages, 7-day trial, no card. |
| A form asks you to print a fax number | Your own number — a shared sending line is not yours to publish. | Solo, as above. |
| Sending to a destination outside the US and Canada | Not available from us yet. We will not pretend otherwise. | — |
The toll-free trap
Agencies publish a lot of toll-free fax numbers — the 800, 888, 877, 866, 855, 844 and 833 ranges. Toll-free numbers are paid for by the called party, and that arrangement often does not extend to calls originating outside North America: the call simply does not complete. Agencies that deal with international filers know this and publish a second number. The CRA is the clearest example: next to the toll-free 1-833-329-1160 for its International Waivers Centre of Expertise it prints 418-566-0323 for senders outside Canada and the United States. If a page offers you both, the non-toll-free number is the one to use from abroad.
The reply direction, in detail
This is the single fact worth more than everything else on this page. A fax transmission under the ITU-T T.30 procedures carries the calling station’s identifier and nothing resembling a reply-to address. When an institution faxes a document back, it faxes the number the original call came from. Consequences:
- A shared sending number cannot receive your mail. If a service sends everyone’s faxes from a pool of numbers, a reply to “your” fax lands in that pool, not with you.
- Some processes are explicitly designed to reply by fax. The IRS, for instance, states in the Instructions for Form SS-4 that where an applicant provides a fax number, the EIN is generally returned by fax within four business days — an outcome that only reaches you if the sending number is yours. (We do not cover IRS forms on this site; the point here is the mechanism.)
- Forms that ask for a fax number mean a number you control. Printing someone else’s on a government form is not a neutral shortcut.
How to send, step by step
- Get the number from the agency's own page. Not from a directory, not from a search snippet. Agency fax numbers are programme-specific and they change. The CRA, for example, publishes different numbers for its International Waivers Centre of Expertise and its Section 116 Centre of Expertise, and SSA publishes none nationally at all.
- Check whether the agency publishes a non-toll-free alternative. Toll-free numbers in the 800, 888, 877, 866, 855, 844 and 833 ranges frequently will not complete from outside North America. Agencies that expect international senders publish a second direct number for them — the CRA prints 418-566-0323 next to its toll-free waivers number for exactly this reason. Use the international one.
- Decide whether you need to receive, not just send. If anything comes back by fax, it comes back to the number you sent from. Buy a number before you send if a reply is expected; send as a one-off if it genuinely is one.
- Prepare the document as a clean PDF. Scan or photograph flat, in good light, in grayscale rather than hard black-and-white, and check every page is readable before you send. A fax transmits an image; a marginal original becomes an unreadable page at the far end.
- Enter the number with its country code and send. Country code 1, area code, seven digits. No 00 or 011 exit code is needed with an online fax service. Upload the PDF, enter the number, send from the browser.
- Read the result, and resend rather than assume. You get a transmission result with the number dialled, the page count and the time. If it failed partway, resend — ideally in smaller batches. Keep the successful result; for anything with a deadline, that record is the only evidence you will have of when the pages arrived.
Why international faxes fail, and what to do about it
A fax call is a live negotiation: the two ends agree a speed and a page format under ITU-T T.30 and then hold a synchronous image transfer for the length of the document. That design assumes a stable circuit. Long international routes add hops, delay and jitter, and some carriers carry fax traffic over IP without ITU-T T.38, the protocol written specifically to carry real-time Group 3 fax over packet networks. The symptom is familiar: the call connects, a page or two go through, then it drops.
What actually helps is unglamorous. Send fewer pages per call. Resend failed batches rather than assuming the first attempt half-arrived. Prefer grayscale, flat scans, which compress predictably. And read the result every time — a fax that failed silently is the only kind that costs you a deadline. We do not publish a delivery-rate promise, because nobody honest can promise one on a call that crosses several networks it does not control.
A plain disclosure
usfax.com is an independent online fax service operated by Mobile Flow Ltd. We are not affiliated with, endorsed by or acting on behalf of the Social Security Administration, the Canada Revenue Agency, the Internal Revenue Service or any other government agency. We cannot file anything on your behalf, check the status of a submission, or give tax, legal or immigration advice. Every agency fact on this page is cited to that agency’s own published material in the Sources section.