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Mark Brezicky /

Skype for Business Online PSTN Conferencing: What do I get?

Skype for Business Online meetings allow for the capability to dial a phone number from the PSTN (Public Switched Telephone Network) to join the audio portion of a meeting from virtually anywhere.  There are several options for dial-in conferencing, including Microsoft’s PSTN Conferencing services.  Both Microsoft service and 3rd party audio conferencing providers (ACP) can be used in the same tenant, but a single user can only be assigned to one conferencing provider at a time.  Microsoft PSTN Conferencing licenses are included in Office 365 E5 plans and are available as an add-on to E1 and E3 plans for an additional fee.  All 3rd party ACP providers deliver separate billing and capabilities.

It is important to fully understand what is included with Microsoft PSTN Conferencing licenses.  There is not a specific cap for the number of dial-in minutes allowed for each PSTN Conferencing subscription, but Microsoft may limit or shut down dial-in or domestic dial-out PSTN conferencing to limit abuse and/or fraud and to maintain service performance. Microsoft also reserves the right to modify or remove PSTN conferencing dial-in number(s) previously assigned to you to maintain good quality of service.  Each tenant is provided a list of shared dial-in conferencing numbers from various countries and regions.  You can also obtain a dedicated service number within the local region of your tenant.

The following chart shows what is included in the license and a link to the currently supported countries and regions. 


PSTN conferencing

Included in plan

Tolled dial-in conferencing


Toll-free dial-in conferencing


Tolled dial-out conferencing

Included for domestic calls


Supported Countries and Regions:

Microsoft does provide an Introductory period that allows Tolled dial-out to additional international locations for a specific period after obtaining the licenses.  For more information, see Skype for Business Online PSTN services use terms

For features not included in PSTN Conferencing licenses, PSTN Consumption billing is required.  PSTN Consumption billing is a means to pay for per-minute usage scenarios.  The following scenarios for PSTN Conferencing require PSTN Consumption billing:


  • Inbound Toll Free numbers used with PSTN Conferencing. Toll free numbers are billed at a rate per minute which varies depending on which country the toll-free number services.
  • Outbound calls from a PSTN conference to an international or domestic location that is not included in their PSTN conferencing subscription.


For a full list of PSTN Consumption Billing rates, see PSTN Consumption Rates.

You can check out our more in our Move it to the Cloud section on our website.


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