8/30/2016 – Additional information/clarification regarding outbound dialing & PSTN Consumption Billing

Microsoft is ever-expanding the availability of PSTN conferencing services within Skype4B Online, adding significant geographic footprint every 6 months, or so.  Despite this increase, there is still some rampant confusion about what is available and where it can be had.  Given how widespread the confusion is – especially amongst customers looking at the service – this post is attempting to clear up some components to allow a more clear picture of the service.

Where can you purchase it?

Your first step is to simply find out if PSTN Conferencing is available for your users.  This boils down to two separate requirements:

  1. Is PSTN Conferencing available where my Office365 tenant is located?
  2. Is PSTN Conferencing available where my end-users are physically located?

Microsoft does have an Office support article on this subject that outlines exactly what countries are available for PSTN Conferencing, but it doesn’t mean they explain it very well.  The list within the Office support article means that if your tenant or end-user is physically located within the list, the user is officially able to be licensed to utilize PSTN Conferencing features.  Microsoft also refers to this list as the ‘sell-to’ list.

I’m not in the list – can I still use it?

This is where things get tricky and very confusing.  In most cases it boils down to these scenarios:

  1. My Office365 tenant is in the ‘sell-to’ list but my end-user is located in a country that is not
  2. My Office365 tenant and my end-user is in the ‘sell-to’ list but callers who dial into my conferences are not

Scenario #1

For each user that you enable within Office365, there is a critical attribute that is required for each user object and that attribute is the ‘UsageLocation’ attribute:


There are many blog posts out there that talk about how UsageLocation is utilized and the PSTN Conferencing feature follows suit with what those other posts talk about.  If your end-user exists in Pakistan, for example, you’ll notice that assigning the license isn’t available (or becomes removed) and it’s all because the UsageLocation attribute doesn’t match up with where the service is available.  I’ve seen some customers try to change the UsageLocation attribute, say in the aforementioned scenario, to utilize the US and after a short while the licensing then works.  The problem with this approach is two fold:

  • The Office365 terms of service don’t officially allow this
  • The UsageLocation attribute is used to help determine domestic VS international calling types when it comes to PSTN billing charges

Since the PSTN Conferencing Service allows dial-out as part of the functionality*, you could end up with tens-of-thousands of dollars of unexpected international call charges when you start altering the UsageLocation.  Take for instance the case where you change a Pakistani user’s location to the US and then they join a conference and have the conference dial back to their local number…  In this case, the call is international and not domestic, because their UsageLocation is ‘US’.  In nearly every scenario, this is not advisable and customers should not change usage locations just to get PSTN conferencing.

*Note:  Prior to September 2016, users could utilize international dial-out functionality within PSTN Conferencing with no additional charges as Microsoft covered call charges under an ‘all-you-can-eat style’ method of billing.  Starting in September 2016 you must have PSTN Consumption Billing enabled within your tenant to support outbound international dialing within PSTN Conferencing.  Domestic outbound dialing should continue to be ‘free’ and does not require PSTN Consumption Billing.

Scenario #2

In this scenario you’ve got true access to utilize the PSTN Conferencing functionality but the callers who join your meetings may not be calling from a location that MSFT has in its ‘sell-to’ list.  This is somewhat less of a problem because Microsoft does actually have local dial-in numbers available in locations that are not included in the ‘sell-to’ list.  Callers can simply dial a number within a country closest to them and reach the conference without much thinking. If the caller can’t find a local, domestic number though, long distance and/or international call charges may apply until Microsoft adds numbers to that geography in the future.

Types of Numbers Available

When PSTN Conferencing originally was released, only shared local toll numbers were available for each geographic region.  Toll-free numbers were not available until recently, with the introduction of PSTN Consumption Billing.  Now that toll-free and toll numbers are available, the PSTN Conferencing feature set is a bit more complete and on-par with other solutions in the market.

Within the types of numbers available, there are three different configurations for those numbers:

  1. Shared Phone Numbers
  2. Dedicated Phone Numbers
  3. Service Phone Numbers

Shared Phone Numbers

This is essentially the toll numbers that have always been available since the introduction of PSTN Conferencing.  These numbers are shared across the entirety of the Office365 infrastructure and any customer can utilize these numbers for inbound calling to their meetings.  Additionally, the language support for the IVR menu system cannot be changed for shared phone numbers.  Microsoft pre-populates these numbers within Office365 and all you must do is simply assign a number to a user account (matching the number’s geography with the location the user is in).  This list is by far the largest in terms of sheer scope of geography.

Dedicated Phone Numbers

This is new(-ish) and includes toll numbers that are specific to your organization/tenant.  These numbers are not shared with other Office365 customers.  To obtain dedicated phone numbers you have two options:

  1. Obtain a phone number directly from Microsoft
  2. Port an existing number from your on-premises PSTN provider to Microsoft

The important thing to note is that while these seem like great options, this option has now been deprecated from usage within PSTN conferencing.  Within this deprecation, Microsoft has begun to separate end-user phone numbers (dedicated phone numbers) and conferencing or auto-attendant phone numbers (service phone numbers) and as a result, dedicated phone numbers are no longer able to be utilized for PSTN Conferencing and must be used exclusively for end-user phone numbers.  The ‘Dedicated Phone Number’ functionality within PSTN Conferencing has shifted to Service Phone Numbers, even though Service Phone Numbers are still dedicated phone numbers.  It’s more of a logical distinction related to billing and capacity support.

Service Phone Numbers

This is new and is intended to take the place of Dedicated Phone Numbers for features such as PSTN Conferencing, Call Queues, and Auto-Attendants within Office365.  Service Phone Numbers allow customers to request dedicated numbers that are specific to their organization/tenant and use those numbers for the aforementioned functionality.  These numbers include toll and toll-free numbers within a subset of the countries that are supported by the Shared Phone Number functionality.  The current countries included in support are:


What is listed is 26 countries where dedicated Service Numbers can be obtained for organizations to utilize for PSTN Conferencing functionality.  Even better is that each Country/Region not only allows toll-free, but it also allows you to request numbers specific to a region within that country.  Where this becomes advantageous is in countries of large geography, say Australia, that may bill calls from Perth to Sydney differently than an intra-Sydney call.  By obtaining numbers that are as local to your users as possible, this will help organizations reduce calling costs as much as possible.  Service numbers will additionally allow you to specify the language utilized for IVR menus, unlike shared numbers.

Despite the Office Support articles saying that porting numbers is an option for Service Numbers, there is a significant limitation in that Microsoft will only allow number porting for countries where PSTN Calling Services are active:


At the current time, that means that only US or UK numbers can be ported.  All other numbers are unavailable to be ported until services are expanded to reach the other geographies.

Shared Number Availability

Given that shared numbers are, well, shared, it may help some customers and architects to see what numbers are available prior to purchasing the PSTN Conferencing service.  Why bother, you ask?  Just because a number is available in a country doesn’t mean that it is a local call for someone within that country.  A user in Melbourne or Perth calling a PSTN number in Sydney is generally billed at a different rate than someone in Sydney calling a PSTN number in Sydney (same goes for the United States intra-region calling or UK intra-region calling).  Microsoft doesn’t publish these numbers publically so the spreadsheet below may help architects in planning the cost structure of a rollout of PSTN Conferencing within Skype4B Online:

Service Number Availability

Given that Service Numbers are very, very new, I haven’t had a chance to put together a full spreadsheet of availability for the 26 countries and the regions supported.  Stay tuned as that will be forthcoming…

Wrapping Up

Hopefully this helps clear up some confusion around PSTN Conferencing.  The service and details are always changing – literally – so this will likely be outdated in a few months.  I will endeavor to keep this updated every 3-4 months or so to reflect the latest information available from Microsoft.

2 thoughts on “Skype4B Online PSTN Conferencing Service Numbers

  1. Chad is so happy you stole this idea and wrote it for him. Unless of course Chad is trying to take credit for something he didn’t do….

    1. LOL! He was absolutely instrumental in helping me develop a large portion of the content, so a HUGE props is definitely due to him. (Thanks Chad Spoolhoff!) He’s got an account here now so hopefully I can convince him to post some stuff in his free time…

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