Nobody answered
The call rang and nothing picked up. Machines are switched off at night, unplugged during office moves, or waiting for paper. This is worth another call, so faxB2B places one automatically — up to three calls in total by default, with pauses of two and five minutes before the retries.
Something answered, but not a fax machine
The number answered and then no fax machine responded. That usually means the number is a voice line, a voicemail box or a switchboard. Redialling cannot help, so the fax stops with a reason saying it was not a fax machine. Check the number with the recipient before trying again; equipment or line configuration can also affect the handshake.
Which one you are looking at
- Retries scheduled, reason says nobody answered: wait for the calls to finish.
- Failed immediately, reason mentions no fax machine: confirm that the number reaches a working fax machine.
- Reason says the number does not exist or is not valid: check for missing digits and confirm that the number is still assigned. Check the number format.
- Reason says the call was declined: the receiving side refused it; confirm the number with the recipient.
Fix a wrong number properly
- Ask the recipient for the fax number specifically, not the main number. The two are often one digit apart.
- Ask for it in international form, starting with a plus.
- Check that no extension was included; a fax call cannot dial one.
- Send one page as a test, then the real document.
When the number is right but nothing answers
Try during the recipient office hours rather than overnight; some machines are powered down outside them. If two attempts on different days both go unanswered, telephone the recipient. A fax machine that has been retired is a common and entirely silent cause, and no amount of redialling will reveal it.