LetterAgent

Mail physical letters by just asking your AI assistant.

Status: LetterAgent is currently in private testing ahead of public launch. Everything on this page describes the service as it works today.

Home > Guides > How to find a fax number

How do I find a company's fax number?

Start on the company's contact page or website footer, where fax numbers often sit next to the phone number. If it isn't there, call the main line and ask: staff usually have the fax number handy. Business directories, invoices, and letterheads are good backups. Always verify the number before you send anything sensitive: a wrong fax goes to a stranger.

Where do companies usually list their fax number?

The contact page. This is the single most common spot. Fax numbers typically appear beside the phone number, email, and address, sometimes under a "Fax" label and sometimes in small print at the bottom.
The website footer. Companies that still fax regularly often print the fax number in the site-wide footer next to the phone number. Scroll to the bottom before you go hunting elsewhere.
Invoices, statements, and letterheads. If you have any paperwork from the company, check the header or footer. Billing departments almost always print their fax number on invoices because customers fax back payment authorizations and remittance forms.
Their directory listing. Google business profiles, industry directories, and association member listings often carry a fax field, though these go stale. Treat a directory number as a lead, not a certainty.
Job postings and RFPs. An odd one, but real: companies that accept faxed applications or bids publish the number in the posting itself.

What if the number isn't published anywhere?

Call the main line and ask. This sounds obvious, but people avoid it and then burn an hour searching. A receptionist or the billing department will usually give you the fax number without fuss: they would rather you fax the right line than tie up their phone asking twice. Ask for the department-specific number when it matters. A company's general fax may sit in an office nobody checks, while the billing, medical records, or legal department has its own line that gets answered the same day.

If calling is not an option, try a site-restricted search like "company name fax" with quotes around the name. Company PDFs (forms, applications, brochures) are indexed by search engines and often contain fax numbers that never made it onto the contact page. Your own email history is worth a search too: the number may be sitting in an old signature block.

How do I verify the number before I send?

This step is the whole game. A fax sent to the wrong number delivers your documents to a stranger, and unlike a misaddressed email you cannot recall it. Verify like this:

Check	How	What it tells you
Call the number from your phone	Listen before you hang up	Fax tones mean a fax machine answers; a human voice means you have the wrong number
Confirm with a person	Ask the department that will receive it	That this is their current line, not an old one printed on last year's invoices
Send a one-page test first	A cover sheet marked "test, please confirm receipt"	That the line works and someone on the other end is paying attention
Watch for fax-detection systems	Some lines answer with voice first	A human greeting does not always mean a wrong number: some systems route the call to fax after a few seconds

One more trap: some companies retired their fax line but left the number on their website. You will get fax tones from a machine in a back room that nobody empties. If your fax goes through but the recipient says they never got it, ask whether the line is still monitored. It often is not.

What about faxing through LetterAgent?

LetterAgent sends faxes to US and Canadian fax numbers: you describe the document to your AI assistant, get a per-fax quote with the page count verified, approve the exact quoted price, and pay once through Stripe. It is currently in testing, so it is described as available in testing rather than a guaranteed send. The verification advice above applies double here, since there is no machine on your desk to redial: confirm the recipient's fax number by phone before you ask your assistant to send.

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Ready to fax it? Fax with LetterAgent: describe it to your AI assistant, approve the exact quoted price, and it is sent.

LetterAgent is a working name. Prices include print, postage, and our service fee. US prices in USD, Canadian prices in CAD (Canadian prices exclude applicable sales tax, added at checkout). Currently in private testing.

Need help? Ask your assistant: it can check a job's status any time. If it ever can't handle something: hello@getletteragent.com