You don't really need your company ID to non-rev on your own airline. You only need your company ID to jumpseat on other airlines. Regardless of what company you work for the FAA's policy is that you can't jumpseat if you are unable to work because you are acting as an additional crew member whether you are in the cockpit or sitting in the back. Travel on your own airline as a non-rev is something you will have to discuss with your chief pilot.