Understanding PSTN Dial-In Audio Conferencing with Microsoft Teams

Microsoft Teams is one product, but depending on what licences/SKU (Stock Keeping Unit) you have different features may be enabled or disabled.

By default, Microsoft Teams comes with the ability to schedule or do ad-hoc online meetings (sometimes called conference calls or web conferences) for up to 250 people. This includes the ability to do VoIP (audio over the PC or mobile clients), Video and desktop sharing.

Your default invite will look like this, with just join details to join from the browser, full client or mobile client. No ability to dial in on a PSTN phone number.

Why might I want PSTN dial-in numbers for my Microsoft Teams online meeting?

VoIP is usually the best option as it incurs no additional cost and gives you wideband audio. However, there are good reasons why you might also want PSTN dial-in numbers for your meetings

Internet connectivity is limited
for those who want to join
A person tried to join on VoIP but is having issues
with their PC or mobile client
The call quality may be better when dialling in – for example on the move on a cell/mobile phone with limited data coverage.
People may find it’s easier and more convenient for their situation

How do I get PSTN dial-in numbers for my Microsoft Teams online meeting?

If you want to include phone numbers to dial into the conference, or the ability to dial out from the conference to a real phone number, you need what Microsoft calls “audio conferencing”. Confusing name considering that is means specifically PSTN (Public Switched Telephone Network) phone numbers for audio conferencing, but that’s what its called.

Depending on the licence of the person scheduling the meeting, this is how you add PSTN dial-in/out for your meeting:

If you have Office 365 E5 typically PSTN Audio Conferencing is included (but there is a specific E5 SKU with PSTN audio conferencing excluded).
If you have Office 365 E1 or E3, Audio Conferencing is available as a standard $4.00/month add-on per user, or you can enable users for Pay Per Minute PSTN audio conferencing.
If you have below 300 users and are on one of the SME Office 365 Business SKU’s or E3, you can also add Telephony and PSTN Audio conference with the Business Voice SKU

You only need the PSTN Audio Conferencing licence for people who schedule meetings. Meeting attendees who dial in don’t need any licenses. Different users in the same tenant can have the standard licence and the Pay Per minute (PPM) licence.

Unlike Skype for Business, the only option to get PSTN dial-in numbers for Microsoft Teams conferences is to buy the service from Microsoft. (There is one exception if you are a GCC customer, in which case you can route in your own PSTN conference numbers).

With this licence your invite will look like this:

Invites only ever show 1 toll number and 1 toll-free number if you have that option enabled. There is a local numbers link which reveals dial-in numbers for many more countries

Users will be given a default invite numbers in the same country as their Office 365 account is assigned. You can change this on a per-user basis in the Teams Admin Center

Which countries can buy PSTN audio conferencing from Microsoft?

Not every Office 365 licence is available to buy from every country. This is particularly true of telephony products where there is lots of additional regulation.

Microsoft maintains a spreadsheet that includes the countries which can buy PSTN audio conferencing, you can download it here Cloud voice feature country/region availability spreadsheet.

Note some countries can only buy the Pay Per Minute variety. At the time of writing standard and pay per minute are available to buy in 78 countries and pay per minute only in an additional 25 countries.

Which countries/cities have local PSTN dial-in numbers for Microsoft Teams online meetings?

Microsoft has a default shared number set for all tenants, which at time of writing covered 64 countries with a default city in each one, usually the capital or a major city.

Shared phone numbers are those phone numbers that are shared with other Office 365 organizations. You can’t change the languages that are used when someone calls into one of these numbers.

You can also elect to add dedicated numbers for your organisation for specific countries and cities, for example, if you want a local number in your home office city. At the time of writing this covered 264 cities around the world for regular toll number and

Dedicated phone numbers are only available to users within your organization. You can change the languages that are used when someone calls into one of these numbers. These are service numbers you assign to Microsoft PSTN Audio Conferencing.

Microsoft maintains a spreadsheet with all countries and regions, you can download it here Cloud voice feature country/region availability spreadsheet.

What does Microsoft Teams PSTN audio conferencing cost?

There are two licences, standard and Pay Per Minute (PPM).

Standard (PSTN) audio conferencing licence is $4 PUPM in the US. PPM incurs no cost per month, but you pay per minute for use.

Standard PSTN audio conferencing licence costs – dialling into a meeting

There is no cost per minute leveraged against the organisation for anyone dialling into the meeting on any standard rate numbers.

If you elect to enable toll-free phone numbers to dial into your meetings (optional and disabled by default), your organisation will pay a per-minute charge

Microsoft has a full downloadable list of rates here

Standard PSTN audio conferencing licence costs – dialling out from a meeting/”call me at”

This is where you are on a meeting and you choose to add someone via calling their phone number, or the person joining the meeting asks Teams to “call me at” a PSTN number rather than joining on VoIP.

“call me at”, e.g. you ask Microsoft Teams to call your PSTN number

PSTN Dial-out from a Microsoft Teams meeting to add a user on a phone number

What is included in your standard licence for dial out?

Beginning December 1, 2019, each (PSTN) Audio Conferencing subscription provides 60 minutes per user per month that can be used to dial out to non-premium numbers in any “Zone A” countries. Previous to December 2019, there was a promotional period of 900 minutes per user per month for Zone A countries.

The 60 minutes per user is pooled in the entire tenant. Your tenant dial-out minute pool size is based on assigned licenses and not purchased licenses. so if you have 100 standard licences assigned, anywhere in the world, all those users/meetings share 100 users x 60 min = 6,000 conferencing dial-out out minutes per calendar month for Zone A. Once beyond those 6,000 minutes in any month, dial out would be pay per minute if that functionality is enabled.

Dial-out calls to countries not included in the “Zone A” country list are charged per minute. The per minute rate is based on the destination of the call and not the organizer’s country of residence or the meeting participant initiating the dial-out call

Which countries are included in “Zone A”?

Zone A countries are listed here. It covers 44 countries.

How can I monitor my outbound dialling minute pool usage?

In the Microsoft Teams Admin Center, navigate to Legacy portal > Reports > PSTN Minute Pools. The Zone A dial-out minute pool will be labelled in the report as “Outbound Calls to Zone A Countries.”

Email notifications will be sent to all tenant administrators of a given customer when the utilization of the tenant’s dial-out minutes pool has reached 80% and 100%.

Can I disable dial out/call me at?

You can elect to disable users from dialling out from Microsoft Teams meetings, or just allow them to dial out to the same country or region as the organiser

Pay Per Minute (PPM) PSTN audio conferencing costs

This option is only open to Volume Licensing organizations. Which means larger organisations that have a direct relationship with Microsoft. You will need to work with your Microsoft AM to enable this option.

In this model, there is no monthly cost to assign the licence to a user, but anytime anyone dials into or out of any meeting for that user.

So, in addition to the person who dials into the meeting paying their usual phone bill, the tenant organisation pays a per minute charge to Microsoft.

This can work out well if the user rarely has meetings where anyone uses PSTN, but occasionally that functionality is needed.

Rates are available from Microsoft here

How are per minute charges billed to the organisation?

Any scenarios that are charged per minute are managed through “communications credits”. Communication credits are a pre paid bucket of credit. It can be a one-time funded bucket or an auto-recharge amount with a minimum balance that will trigger a purchase for that recharge amount. Communications credits are available in 93 countries at the time of writing.

Communication credits are used for the following:

Add toll-free numbers to use with Audio Conferencing meetings, auto attendants, or call queues. Toll-free calls are billed per minute and require a positive Communications Credits balance.
Dialling out from an Audio Conference meeting to add someone else from anywhere in the world.
Dialling out from an Audio Conference meeting to your mobile phone with the Skype for Business or Microsoft Teams app installed to destinations that aren’t already included in your subscription.
Dial any international phone number when you have Domestic Calling Plan subscriptions.
Dial international phone numbers beyond what is included in a Domestic and International Calling Plan subscription.
Dial out and pay per minute once you have exhausted your monthly minute allotment.

Microsoft maintains a spreadsheet with which countries can use communications credits: Cloud voice feature country/region availability spreadsheet.

How can I see an itemised bill of PSTN audio conferencing calls and costs?

The Teams Admin Center offer a per call breakdown of any PSTN conferencing calls and costs

You can also export the call records as a CSV.

Can users have a static PSTN conference ID?

On some systems, users can elect to have a default static conference ID, so that users can get to know their ID for “their bridge”. Microsoft Teams does not support this for security reasons. Each meeting will generate a unique dynamic ID.

When you create a reoccurring meeting, that reoccurring meeting will have the same conference ID for the life of the meeting (until the end date of the reoccurring meeting).

A conference ID will contain 7 digits, and you can’t change its length or define it for a particular user.