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8x8 Support

Troubleshooting Internet Fax Issues


There is a failure on the first attempt of sending an internet fax. 

Applies To

  • 8x8 Work for Desktop
  • Internet fax



 Note: Up to 3 faxes can be sent at a time and if any of those faxes does not finish within 60 minutes to make space for more faxes, the user can send up to 3 more faxes again irrespective of what happened to earlier 3 faxes in transit.

Double-check that the internet fax is within the limits and restrictions of the service. Listed below are the restrictions and limitations. 

  • Total fax size sent cannot be greater than 20 MB.
  • Maximum of 5 files per fax.
  • The maximum page count of fax attachments in fax email notifications is 200 pages.
  • Internet fax notifications with attachments are only available with faxes up to 200 pages (inbound only).
  • Any fax exceeding 20 pages can still be downloaded from 8x8 Work For Desktop.
  • Must use 11 digits for sending outbound fax. If a Number is Incomplete error appears, ensure that the user is sending to a fax number using 11 digits (e.g., 1 + 10-digit number).
  • Files sent cannot include any special characters or letters with accents. (Ex: ñ) 

Adjust the fax so that it is within the limits and it should send correctly.

If the issue continues after checking that the internet fax is within the limits of service, contact 8x8 technical support.


  • File attachment does not fall within internet fax limitations.
  • The fax destination is unable to receive faxes.
  • The fax server may be under high load.
  • Possible incompatibility or issue with the receiving fax machine.
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