Microsoft introduced Microsoft 365 Business Voice in November 2019 for the UK and Canada, and from 1 April 2020 it’s also available in the US. 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, F3, A3, E3) or a Microsoft 365 plan (Business, F3, A3, E3). It’s limited to up to 300 users in an organisation, and the price per month is $20 per user. There’s also an International Calling Plan available for $12 per user per month. Business Voice without a calling plan also launches on 1 April, 2020 in around 70 additional countries.
Microsoft Calling Plans let users make and receive phone calls. From a licensing perspective there are Domestic and Domestic and International Plans available as User Subscription Licences and all users need to be licensed with a Phone System User SL too. The most recent availability of Calling Plans is in Canada (http://bit.ly/2IJ2MZM) from 1st May 2018, where calls to the US (and vice versa) are considered to be domestic .If you’re interested in a spreadsheet which shows availability throughout the world and how many minutes are included in the different regions, then this is download-must: http://bit.ly/2JbycHs.