Why did my fax fail?

Troubleshooting fax failures

Stacy Lane avatar
Written by Stacy Lane
Updated over a week ago

Faxes can fail for a variety of reasons, such as sending to a non-working or non-fax number, a recipient listing their number on the National Do Not Call List, a recipient line being continually busy or out of paper, or if there is noise or interference on the line. Kno2 retries faxes a minimum of 5 times. If a released fax has a 'Failed' status, you can hover over the status for more error details.


Verifying a Fax Number

You can verify that the number is a working fax line by dialing it and listening for a fax tone. A few indications the line is having issues include:

  • The call receiving a busy signal.

  • The call ending before a connection is made.

  • The call ringing without ever connecting.

  • The call being answered with an "out of service" message.

  • The call being answered by a person or an auto-attendant/voicemail.

  • The call being answered by a reorder tone (fast busy signal) indicating technical issues.

If you encounter consistent failures to a 'good' fax number, please ensure you are utilizing Default as the Caller ID number. This is common number for the outbound Caller ID to improve deliverability.


Additional Information

If you need more information about a fax failure to a good number, please reach out to us in chat or at support@kno2.com and provide the following details:

  • The URL of the failed fax.

  • If the URL is not available, provide the following information for two failed faxes for each failing number you wish to have reviewed:

    • Date (must be within the last 24 hours)

    • Time

    • To number

    • From number

    • Failure reason, if available

Need to retry a failed fax to a good fax number? You can Forward a Sent Message to send your original attachment again!

Did this answer your question?