Can I switch to a different Office 365 plan or subscription?
Office 365 offers a variety of plans to meet the needs of different organizations. If you already have a subscription to Office 365 and are thinking about changing plans please read on.
You can switch plans:
- In the same service family -- Use the Switch plans wizard in the Office 365 portal to upgrade from one plan to another within a service family. For example, if you are currently subscribed to Office 365 Small Business, you can move to Office 365 Small Business Premium, or from Office 365 Enterprise E1 to Office 365 Enterprise E3.
x - From a standalone plan -- Use the Switch plans wizard to move from a standalone plan to an Enterprise plan; for example, from Exchange Online to Office 365 Enterprise E1.
x - To a different service family -- You can switch to a plan that isn’t in the same service family, but you will need to switch plans manually, without using the Switch plans wizard.
Read all the details here