Office 365 Developer : Required permissions/plans for an Office 365 account to access using Office 365 REST APIs
Are you an Office 365 developer and want to use Office 365 APIs such as mail, contacts, calendar, and files to access then you need to have the following permissions/part of plans:
Permissions: To access you need to have an Office 365 business account with global administrator privileges.
Plans: Also this can be one of the following plans:
Office 365 Midsize Business
Office 365 Enterprise E1, E3, E4, E5 or K1
Office 365 Education A2, A3, or A4
Office 365 Developer
If you don’t have the above, then you will get an error when you try to connect with Visual Studio (using Office 365 Tools > Add > Connected Service).
Hope this helps.