The plan presented in this page is a combination of Skype for Business Plan 2 and a Dial-in Conferencing add-on (also called PSTN Conferencing). The Dial-in Conferencing features can also be added to the Office 365 Business Premium, Essentials, E1, E3 and E5 plans at extra cost. Ask our Account Manager for more details.
No. Only the meeting organizers will need the Skype with Conferencing plan to send meeting invites that include dial-in phone numbers. Attendees who don’t have the Skype plan will be able to join from any browser or mobile device using the free app.
There isn’t a resource that contains a listing of all of the dial-in numbers for Audio Conferencing. If you want to see if there are dial-in phone numbers available in your area or country/region, use the Skype for Business admin center > Voice > Phone Numbers, click Add, and then click New Service Numbers. Use the lists for Country/Region, State/Region, and City to filter your search. Also, if you are looking for toll-free service numbers, select Toll-Free from the State/Region list.