Station ID

When the from filter finds a fax by phone, why most faxes arrive with no sender ID, and why a default ID is shared.

The from filter finds a fax by phone only when a sender ID reaches Faxbeep with the call. For most faxes by phone, none does.

What the sender ID is

The ID of the machine that sends a fax is its TSID, set as the station ID of the machine. It is a fax number or a short name. Faxbeep shows it as the sender of the fax, and from matches it. See TSID.

The CSID is the ID of the machine that receives the fax. It is not the ID of the sender, and you cannot use it to find your fax. See CSID.

Faxbeep has no field that you can set to tag your test. The sender ID is what your machine or your fax provider sends, and Faxbeep cannot change it.

Most faxes by phone have no sender ID

About 4 in 5 faxes by phone arrive with no sender ID. Whether it arrives depends on your machine, your fax service and the phone network, not on Faxbeep. When none arrives, faxbeep.com shows the sender as “Unknown”, and the API gives "from": null.

What arrives with the call	from in the API	Find your fax by
Nothing	null	since and page_count
A phone number	The number, masked	from with the full number
A station ID (a name)	The ID, as on the site	from with the ID, if only you use it

A test by email always has a sender: the address in the From line. See Find your fax.

To learn what your setup sends, send one test and look at the sender on faxbeep.com. If it says “Unknown”, use since and page_count. ?from=Unknown lists the tests with no sender ID, but they are from many senders.

How from matches

Rule	Example
Full value only	[phone] matches. 5550123 does not: there is no prefix and no wildcard
Case	FrontDesk, frontdesk and FRONTDESK match one sender
Spaces	Front Desk matches FrontDesk. The spaces of a station ID are removed
Plus sign	[phone] and 15555550123 match the same number. Send + as %2B
Masked value	The masked form that the API and the site show does not find your fax

A station ID can have 20 characters at most, and it arrives with no spaces: Front Desk shows as FrontDesk.

A default ID is shared

Many machines and fax services send a default station ID, such as test, Fax or mFax. Many other senders use the same ID, so ?from=test&limit=1 can give the fax of a different sender. There is no block list. Always compare received_at and page_count with what you sent, also when you filter by from.

If your machine or fax service lets you set the station ID, set one that only you use, for example a name with a random part. Then from finds your fax.

Next

Test in CI

A script that waits for your fax, with or without a sender ID.