Can someone help me understand PSTN Conferencing?


I'm trying to understand exactly how PSTN Conferencing works. We host a monthly meeting of our board of directors. Some attend in person, some call in via an AT&T conference call number. We would like to offer board members the ability to participate via video conferencing, or to just call in on the phone. Wondering if PSTN Conferencing can replace/enhance our current setup.


  1. Would Skype for Business with PSTN Conferencing accomplish this for us?
  2. Does every meeting participant need an E5 license, or just the meeting convener?
  3. Is there a cost for PSTN besides the E5 license cost (e.g., per minute? per caller?, etc)?


7 Replies
Hi Edward.

There is a technet page regarding PSTN conferencing in Office365:

Let me know if you need more information.



Yes PSTN conferenceing would work as a replacement for your setup.

Only the meeting organiser needs an e5

The only costs you should incure will be if you assign a toll free number


Thank you Erdem and Richard! These are both very helpful replies. One thing I can't seem to find information about though is the cost for assigning a toll free number. Is this information available somewhere? Thanks!

You do not get charged for a toll free number only it's use.


You need to setup consumpution billing


The PSTN consumption billing table is here:




Thanks. Sorry for the amateur questions! I hope this is my last one... :) in looking at the table, it looks like Toll Free for Tenants in the United States is $.013 per minute. Is this $.013 for each caller using the line? Thanks!

Yes each person calling in using the toll free number would pay the per minute charge so 5 people call in using it you would have 5 call charges.

Also an extra cost may be incurred if you go over the minutes bucket which is combined/shared amongst all the license you have.  It is all given in the Service Description.


What is really nice is the ability to call out to other phones.  It sort of a way for PSTN call out if you do not need DID too.