In addition to adding an individual and main line options you should consider adding carrier as an option and then making email optional alot of carriers don't have specific emails for claims, billing etc. they make that on their website so you should add a website page option or just leave that option as not required so you can just bypass and allow for the phone number. In addition, you should be able to sort within the directory, maybe consider adding a search option. Another idea is to create a nickname for main department lines or allowing the ability to add a custom department.