Hi Steph,
Before we address the issue, could you let me know which Office 365 subscription you’re using?
Because different subscriptions have different ways to activate Office, I suggest you select the correct channel for solving the issue in the most efficient way. Our forum focuses on Office 365 for Business plans. If you’re using Office 365 for Home/Personal/University, could you post a new thread in our dedicated Office 365 for Home, Personal and university forum for further assistance?
To post a thread there, please click Participate> Ask a Question.
If you’re using the Office 365 for Business plan, could you provide us with the following information so that we can assist you further?
1. Which version of Office is installed? E.g. Office for Mac 2011, Office for Mac 2016 Preview
2. Could you try resetting your password and check if you can activate Office?
3. Could you try whether you can activate Office on another computer?
Thanks for your understanding and cooperation.
Best regards,
LingYu Sun