You can call the following countries/regions:
Both landlines and mobile phones: Canada, China, Guam, Hong Kong SAR, Puerto Rico, Singapore, Thailand, and the United States.
Landlines only: Andorra, Argentina, Australia, Austria, Belgium, Brazil, Brunei, Bulgaria, Chile, China, Croatia, Colombia (excl. Lex), Costa Rica, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Guadeloupe, Hungary, Iceland, Indonesia (Jakarta), Ireland, Israel, Italy, Japan, Korea, Latvia, Lithuania, Luxembourg, Malaysia, Malta, Mexico, Morocco, Netherlands, New Zealand, Norway, Panama, Paraguay, Peru, Poland, Portugal, Romania, Russia, Slovakia, Slovenia, South Africa, Spain, Sweden, Switzerland, Taiwan, Turkey, United Kingdom, and Venezuela.
Skype minutes are not included with Office 365 in Algeria, Armenia, Azerbaijan, Bahrain, Bangladesh, Belarus, China, Côte d’Ivoire, Egypt, Ghana, India, Kazakhstan, Korea, Kuwait, Lebanon, Libya, Morocco, Namibia, Pakistan, Qatar, Russia, Taiwan, Tunisia, and United Arab Emirates.
Note that special, premium, and non-geographic numbers are not covered by Skype minutes. Additionally, it isn’t possible to place emergency calls.