@HOFH ,
Currently, no official document has instructions to migrate Microsoft Teams. It can only be realized by 3rd party tool. For more details about tenant-to-tenant migration, you can refer to this article: https://learn.microsoft.com/zh-cn/microsoft-365/enterprise/microsoft-365-tenant-to-tenant-migrations?view=o365-worldwide.
In fact, it is a challenge to migrate Microsoft Teams because the most data isn’t stored in Teams. It’s actually stored in SharePoint team site, Exchange team mailbox, Exchange mailboxes of individual users, OneDrive for Business of individual users, OneDrive organizational document library, Azure, Stream, Third-party storage provider.
Meanwhile, this case discusses the topic about Teams migration. You can refer to it.
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