Microsoft introduced Microsoft 365 Business Voice in November 2019 for the UK and Canada, with plans for global availability in 2020. This is a single Add-on licence which includes access to Phone System, Audio Conferencing, and a Domestic Calling Plan, and can be added to an Office 365 plan (Business Essentials, Business Premium, A1, E1, A3, E3) or a Microsoft 365 plan (Business, A3, E3). It’s limited to up to 300 users in an organisation, and the price per month is £12.00 per user.

Find the original announcement here: http://bit.ly/2Yt80gU and a useful overview page here: http://bit.ly/2Yw4LoR.