One downside of the free service is that it includes a cover page with the FaxZero branding on all your faxes. If you opt for the paid service, you can send up to 25 pages per fax, without the cover ...

The online fax service features local fax numbers, customizable fax cover sheets, complimentary resending for any failed faxes, fax scheduling, and filtering out suspicious or anonymous faxes.

Then choose up to ten files to attach and fax. Note that these files can be in JPG, PDF, or Doc format. Checking "Use No-Ad Free Cover Page" at the top will add a cover page to your fax.