When migrating from Google Workspace to Microsoft 365, it’s best to plan the transfer before moving user accounts. Start by checking the number of mailboxes, available storage, and the data you need to move, including emails, contacts, calendars, and Google Drive files. You should also verify user permissions and test the migration with a small mailbox first. For organizations that want to simplify the process, a "SysTools Google Workspace to Microsoft 365 Migration Tool" can help transfer supported mailbox data without having to migrate each account manually. Before choosing a solution, confirm which data types it supports and whether Google Drive files need to be migrated to OneDrive separately. After migration, verify the emails, attachments, calendars, and files before decommissioning the old environment. Keeping the original accounts available until everything is checked can help avoid unnecessary disruption.