Most faxes that fail do so for one of four reasons: the line is busy, nobody answers, the call drops partway through, or the number is not a fax machine. The first three are often temporary, so Faxsure tries again automatically, up to 3 attempts in total. A number that is not a fax machine, or does not exist, will not work on a retry, so the app stops at once and tells you. Either way, a fax that is not delivered goes back on your balance automatically.
Busy
The recipient’s fax line was in use.
What happens: the app retries a few minutes later, up to 3 attempts in total. What you can do: if all 3 attempts were busy, try again free later in the day. For an agency, check whether it gives more than one number for your case; some list a number per state or per office. The directory of official fax numbers shows which number applies to whom.
No answer
The call rang out, or something answered but did not respond like a fax machine. Fax machines identify each other at the start of the call: under ITU-T Recommendation T.30, an answering fax machine sends an answer tone, a “continuous 2100 Hz” tone, and the two machines then exchange their capabilities. The standard sets how long they keep trying: “Time-out T1 defines the amount of time two terminals will continue to attempt to identify each other. T1 is 35 ± 5 s”. If nothing identifies itself as a fax machine in that time, the call ends without a fax.
What happens: the app retries, up to 3 attempts in total. What you can do: if it never answers, the fax machine may be switched off or not connected. If something answered but did not respond like a fax machine, the number may be a voice line: check it against the form’s instructions or the letter you are answering. Then try again free, or call the recipient’s voice number and ask.
The call dropped or the line was poor
The call started, but the connection broke or was too noisy for the pages to get through. The receiving machine reports pages it did not receive well, and the call can fail if the line stays bad.
What happens: the app retries, up to 3 attempts in total. What you can do: try again free.
Not a fax machine
The line answered but reported that it cannot take a fax. The number may be a phone line rather than a fax line, or a line set up for something else.
What happens: the app does not retry, because the same number will give the same answer. It says “Not delivered” and why. What you can do: check the number against the form’s instructions or the letter you are answering, then change the number and try again free.
The number does not exist
The number is not in service or is not a valid US or Canadian number. US and Canadian numbers have 10 digits after the country code 1, in the format “NXX-NXX-XXXX where N = 2 to 9 and X = 0 to 9”, as the Canadian Numbering Administrator describes the shared numbering plan. A missing or extra digit gives a different, often unassigned, number. Fax number formats in the US and Canada explains the parts.
What happens: the app does not retry. What you can do: correct the number and try again free.
What you get back
When a fax is not delivered after its last attempt:
- the fax goes back on your balance automatically, and you get a notification with the reason in plain words;
- for 24 hours you can try again free, or change the number and send again;
- a fax paid with pages from Send or Plus gives its pages back too.
The document is kept for those 24 hours so you can retry without adding it again, then deleted from our servers.