Hi Dan Thomas,
I understand that the difference between the number of installations and the number of devices you can actively use can be confusing.
With Microsoft 365 Family, you can install the Microsoft 365 apps on additional computers, but each person can be signed in on only five devices at the same time. Computers, tablets, and phones all count toward that five-device limit for the individual user.
If you are setting up a new computer and have already reached the limit, you do not need to uninstall Office from every device. Simply sign out of an older or unused device through your Microsoft account, then sign in on the new computer.
You can review your subscription sharing and devices at https://account.microsoft.com/services. If you need any additional information, please feel free to ask. Thank you so much for your understanding.
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