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We’ll be posting tips, fixes and hints for all our major technologies including Microsoft Teams, Skype for Business Server & AudioCodes Session Border Controllers.

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How To Make An External Call On Microsoft Teams

Jun 10, 2020 | Microsoft Teams

Microsoft Teams has experienced an explosion of user growth over recent months. With an increase of 70% being recorded, bringing the platforms daily active user count to 75 million people (April 2020) it has made Teams one of the most widely used collaboration platforms across the globe.

Whilst Microsoft Teams contains several powerful communication tools, such as chat, channels, video conferencing and deep integration with other Microsoft platforms, there is an increasing amount of interest in it’s external calling capabilities. Have you ever wondered how to make an external call on Microsoft Teams, if this is possible and if so, how? The good news, is that this is indeed possible and that the functionality now available, compared to when Teams was originally released, has come on leaps and bounds.

If you’ve taken time to look at the “Calls” tab in your Microsoft Teams client, you’ll likely have noticed that whilst you can call people inside your organisation, there isn’t any option to call an external number. So what do you need in order to be able to call a landline, mobile or international number directly from your Teams client? We’ve provided a break down below to help you understand the components required. The good news, is that adding external calling to Teams doesn’t require you to climb a mountain. It’s Phone System functionality can be quickly provisioned, providing either you or your organisation with the ability to make external calls in a matter of hours.

Office 365 Subscription Licensing

Yes, we can hear you shudder at the word “licensing” however it isn’t all that bad. Whilst Microsoft are long known for their often confusing licensing requirements, adding calling fortunately isn’t one of those. If you have you Microsoft Teams already, then you have an Office 365 subscription. In order to unlock the external calling functionality of Teams, otherwise know as Phone System, you need to add an extra per-person license to your subscription to achieve this. The following Office 365 subscriptions permit you to add the required Phone System licensing.

  • Office 365 Business Basic
  • Office 365 Business Standard
  • Microsoft 365 Business Premium
  • Office 365 E1 / E3
  • Office 365 E5 (Phone System Included)
  • Office 365 F1
  • Microsoft 365 A1 / A3
  • Microsoft 365 E3

Phone System Licensing

Business Voice

The Phone System add-on license is available in two different flavours. The flavour you choose does depends on a few different factors such as your organisations size and the subscription type you have from the list above. The first option you have is Business Voice, which was launched last year. This license provides the following features for a fixed monthly cost per user, for up to a maximum of 300 users only.

  • Cloud-based phone system with advanced features including call transfer, multi-level auto attendants & call queues.
  • Domestic calling plan including 1,200 outbound minutes per user within UK (Premium rate numbers not included)
  • Dial-in audio conferencing for up to 300 people per meeting.
  • Call from anywhere, on any device through the Microsoft Teams app on desktop, mobile, web, and desk phones.

The Business Voice license currently costs £12.00 per user and provides the most “bang for your buck” given it also includes dial-in audio conferencing, which is normally a separate purchasable license on it’s own. When the Business Voice license is assigned to a user account along with a provisioned telephone number, your Microsoft Teams client will then display the external calling dial pad.

External Calling Dial Pad - Microsoft Teams Client

If you’re not familiar with the included audio conferencing feature, it essentially adds a separate external telephone number that meeting participants can call if they are unable to join the meeting via a device, such as a PC or laptop. This number will be the same for everyone using Teams in your country. For example the number detailed below is the same for everyone in the UK, it is the conference ID that denotes the unique meeting itself.

Phone System

If you’re over 300 users in size, Business Voice isn’t an option you can take. In this case, you will need to add what we refer to as the traditional Phone System add-on license priced at £6.00 per user per month. This license can only be added to Enterprise Plans such as an E1 or E3. If you have an E5, you’re already good to go as this includes the Phone System license.

In this scenario however the Phone System add-on license it does not include a calling plan, which provides your calling minutes and this needs to be an additional purchase. There are several calling plans available for purchase, which are detailed below.

  • Microsoft 365 Domestic 120 Calling Plan (120 minutes) – £4.20
  • Microsoft 365 Domestic Calling Plan (1,200 minutes) – £9.00
  • Microsoft 365 Domestic and International Calling Plan (1,200 UK – 600 International) – £18.10

The minutes detailed above are pooled between all licensed users, meaning if one user runs out of minutes they can still continue calling by drawing minutes from the central pool. For example, if two Domestic 120 Calling Plans were purchased, there would be a total of 240 minutes available to both users. However, it is important to note that minutes are reset each month and are not cumulative over time. If you purchase a UK only calling plan, you can still call international numbers by topping up Communication Credits. These are essentially a pot of money available to draw international calling costs from.

This Could Get A Little Expensive?

At Siplifi, we like to be honest, no matter how much we love Microsoft. Calling Plans can be an expensive approach depending on the size of your organisation and the combination of calling plan types you may need. If you’re an organisation that performs a high amount of national and international calls and you’re over a hundred users in size, the financial feasibility can be a push. This compounded especially if you already have an investment in an existing telephone system (PBX).

Direct Routing

Microsoft do provide an alternative, called Direct Routing, which allows you to choose who provides your calling minutes. No matter which Office 365 subscription or Phone System add-on you have, this gives you several advantages.

  • If you already have an agreement with a telecoms provider for SIP channels & minutes these can likely be reused
  • Not confined by a set amount of minutes per month or limitations making international or premium rate calls
  • You won’t be subject to potential Microsoft Calling Plan price rises
  • Retain analogue devices such as fax, franking machines, along with chip & pin readers.

In order to use Direct Routing you need a certified Session Border Controller (SBC), this is a piece of software that sits between the telecoms provider and Microsoft Teams, think of it as a translator. If you already have a Session Border Controller this may be suitable for Microsoft Teams assuming it is from a certified vendor. If you don’t have an SBC, we provide a hosted Direct Routing service using AudioCodes Session Border Controllers. This service can connect to your telecoms provider and Office 365 tenant, meaning you can get up and running with external calling in Teams, just as quickly as you can with Microsoft’s Calling Plans.

In terms of licensing for Direct Routing, “Business Voice without a calling plan” can be purchased for £6.00 per user, per month. This still includes all the features detailed above, with the exception of the 1,200 minute allowance. This is still however only available to those organisations under 300 users, those over this number will still need the regular Phone System license.


In world of external calling with Teams, there isn’t a right or wrong answer. Whether you choose Calling Plans or Direct Routing, it really does depend on both your organisations requirements and budget. The choice between Calling Plans and Direct Routing can be a tricky one. To help you decide we’ve created a free whitepaper detailing the differences. We hope you’ve found our How To Make An External Call On Microsoft Teams article helpful, if you need any further in information or assistance, get in touch using the contact form below.