At the end of 2015, Microsoft released Office 365 E5 – an enhanced version of its Office 365 suite. Whilst information around E5 has been available for the past 6 months, many customers are still unsure about what E5 can offer them, and about whether or not they should upgrade.

At Trustmarque, we believe that IT should be simple. Customers should be able to easily understand the options available to them, without getting bogged down in jargon and complex pricing tables. In the name of simplicity, therefore we’re here to give you the low down on all things Office 365 E5.

Today, we will be focusing on the extensive communications offerings available through Office 365 E5.

A New Age of Skype for Business

Perhaps one of the most exciting aspects of Office 365 E5 is the new set of communications features available. Users that opt for Office 365 E5 will gain access to Cloud PBX, PSTN Calling, and PSTN Conferencing – providing those services are available in their geographic area.

Initially, these features were only available in the US. But as of July of this year, PSTN Calling, Conferencing, and Cloud PBX are all available in the UK.

But what exactly are they?

Cloud PBX

Cloud PBX (Private Branch Exchange) allows users to make, receive, and transfer calls from any device – all they need is a mobile connection.

The ability to use your desktop, laptop, or tablet as a phone is a welcome innovation in the world of mobile working.  Employees that travel regularly no longer have to worry about remembering their mobile phone – all they need is their laptop or tablet, and voice calling is available with a simple press of a button.

PSTN Calling

 PSTN (Public Switched Telephone Network) Calling through Skype for Business. With PSTN Calling through Skype for Business, users can now access all the benefits of PSTN calling – caller ID, excellent line quality, and the other features of traditional telephone calls – with all the mobility, flexibility, and cost savings of VoIP calls.

On-Premise PSTN Calling for Skype for Business has been available for a while, but in many cases purchasing, configuring, and supporting the infrastructure required to accommodate this negated the cost savings that are traditionally associated with VoIP calling. With PSTN Calling in the Cloud, however, that is no longer the case.

With PSTN Calling through Office 365 E5, users are provided with their own PSTN number, which can both dial and be dialled from any ordinary phone. Moreover, Microsoft has partnered with a range of global telecom partners, including BT Global Services and Orange Business Services, in order to provide users with high-quality and secure connectivity.

PSTN Conferencing

PSTN Conferencing allows meeting attendees to dial-in to Skype meetings from virtually any device, making pesky conference calls easier than ever. Meeting organisers can also dial-out to attendees to connect them to the audio portion of the meeting, allowing users without Skype for Business to join the call.

With PSTN Conferencing, organisations can consolidate their existing conferencing solutions into one, simple package – simplifying IT, reducing support costs, and empowering employees to work from any place, on any device.

Let Trustmarque Help

If you would like to know more about PSTN Calling, Skype for Business, or any of the other fantastic features available through Office 365 E5, speak to one of our experts today. Simply email us at, or speak to your Account Manager to find out how we can help.


This post is part of our Office 365 E5 series. To read the previous post, click here.