To make it simple for your organization to invite each other, you may upload a company directory that serves as a pre-populated Address Book for your hosts. They may still add other hosts to their individual Address Book, but the Company Directory will be the same for all hosts. 

First you will need to export the contacts into a CSV file using the format provided in the attached example. Once you have this file saved, simplly drop it or upload it into the appropriate area. 

You will see a message if the upload is successful or if it failed.