Dear Susannah Morrison
Thank you for reaching out to the Microsoft Q&A forum.
We understand that your recent purchase of a Microsoft 365 subscription under your personal email address has inadvertently linked to a previous work account, which you no longer have access to. This situation can occur due to residual credentials or prior associations stored on your device or within Microsoft services.
To address this issue, we recommend that you first sign in to your Microsoft account at https://account.microsoft.com using your personal email. From there, you may review any associated accounts and attempt to remove the unwanted work account through your account settings or within the Microsoft 365 applications.
Additionally, we advise checking your system’s Credential Manager to ensure that no outdated credentials are stored that could be causing this linkage. To do this, open the Control Panel, navigate to Credential Manager, and select Windows Credentials. Locate any entries related to your previous work account and remove them. This will help prevent automatic associations when using Microsoft 365 services.
As you are a licensed Microsoft 365 subscriber, you may be eligible for direct technical support. We encourage you to contact Microsoft Support via https://support.microsoft.com/contactus, just ensuring choosing the right subscription that you're using.
Please have your Microsoft account details and proof of purchase available to facilitate the support process.

I hope the details provided will assist you effectively.
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