Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello @Richard Pohl
Welcome to the Microsoft Q&A Community!
Thank you for contacting us. I understand you activated Office Professional Plus 2021 and later purchased Office Professional 2024, which turned out to be an LTSC edition. I want to clarify how Professional Plus and LTSC licensing works.
Office Professional Plus 2019 and later, including LTSC editions, are volume licenses intended for business use and are distributed through Microsoft’s volume channels. They are not sold as individual consumer retail products. When a Professional Plus key is sold to an individual, it is often a portion of a larger volume key pool. If that pool reaches its activation limit or is later blocked, activation on a new device can fail, and remediation must be handled by the seller or the organization that owns the volume license. Please refer to Microsoft’s Q and A discussion on moving Office 2021 Professional Plus, which explains MAK limits and why reactivation can be blocked after device changes. Office 2021 Professional Plus Lizenz umziehen
(My apologies for the discussion being in German, please use a reliable translation tool to help with interpretation.)
If you need to remove Office Professional Plus 2021 from your device before reinstalling your preferred edition, this thread on uninstalling Office Professional Plus 2021 provides relevant guidance and considerations you should review prior to reinstall: How to uninstall Office Professional Plus 2021 version and Save License for future Use
Based on the above, the correct support path is to contact the place of purchase if your key came from a third‑party seller or reseller, because only the volume license owner can adjust activation counts or provide a replacement entitlement when a volume pool is exhausted.
Please review the two articles above for full context and next steps. Let me know if you need any further clarifications.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.