Within my current company, we currently use a hosted Skype solution which also has some functionality around hosted PBX.  This was so a few years ago we could ditch our traditional ISDN based telephony solution with a cloud hosted PBX solution.  There were a couple of reason we chose this route – first reason was, that they cloud PBX functionality from Microsoft just wasn’t available and secondly we wanted to be able to work anywhere in the world and take our number with us (plus it solved a tricky DR problem we had with the legacy phone system!).  However, given the impending introduction of PBX within Teams, we are now looking to moving our Skype back into Office 365 and getting the hosted PBX with Microsoft.  Due to being a Microsoft partner, we get 35 E3 licenses included for internal use and the original thought was that we would have to pay for 50 E5 licenses in order to get the cloud PBX solution.  However, that is not the case – you can indeed add the cloud PBX solution to your existing E1 or E3 licensing:


Now don’t get caught out here, thinking that you can add the cloud phone system for £6/user/month and get all the functionality that you might get from another hosted provider.  Yes, you get the ability to dial out to landlines and mobiles etc, but what you don’t get is audio conferencing.  Now, all audio conferencing is, it gives you the ability to be able to send a Skype meeting request to someone that may not have access to Skype and they can join in using a traditional method like a landline or mobile etc.  That particular add-on will cost you £3/user/month.

It’s not until you start really reading what comes with E5, that you might think it is worth upgrading your licenses from E3 to E5.  Yes, it is an extra £13/user/month for an E5 license, but given that you need to spend £9/user/month if you have E3 and want to get the same hosted telephony features, then an extra £4/user/month isn’t really that much money (well that may depend on the number of users that you have!).  Something else to consider is, if you are using a 3rd party E-Mail filtering service like Mimecast for example, you could potentially save money by ditching your existing E-Mail filtering service and using EOP with ATP that comes with the E5 license.  At that point, the cost of E5 may break even or actually save you money!

Also do not forget, that the cloud phone system at £6/user/month does not include any voice minutes to landlines etc – you need to purchase a calling plan which is an extra £9.10/user/month.  This cost (if you want to include it), needs to be added to both E3 and E5 licenses – E5 by default does not have any inclusive minutes to landlines.