Open the settings for the User extension being used to send faxes. Open "Outbound Calls/Faxes" tab, then open the "Fax Settings" section, then select the "Edit" button under the Fax Number. You should see a list of main numbers, including your fax number - select the number you want showing as your fax number on the fax cover pages.
Thank you for your response. I forgot to mention in my POST, the number associated with the FAX Extension is not the actual FAX NUMBER. Our FAX number is toll-free 888-235-8405. With that being said, it does not appear as a number I can select. Doesn't make sense to me but maybe you can shed a little more light on this matter. Thank you.