I have recently taken over administration of a client as their Partner of Record. The client previously purchased Business Premium licenses directly from the O365 portal but now desires to work with me to provide and administer their subscriptions.
I have attempted to add an additional BP license to their existing subscription (14 BP), however it tells me the key cannot be added (and there are no add-ons utilized by the existing subscription).
Please advise why I cannot:
1. Add this to the existing subscription
2. OR, add this as a new subscription.