Migrating Office 365 services to another tenant. Checklists, tools, things to read?


A client of mine is asking about migrating his domain (approx. 300 users) out of a bigger tenant with several thousand users into his own tenant. This is an educational institute with students, teacher and administration. 

Teams is key in that organisation. Sharepoint is less used, but still there are sites. Exchange, of course and and a few additional 3P services linked in. 


I am looking for advice:

  • How do I do a proper inventory on what is being used in this environment? 
  • What especially would I have to look for that will be important during the migration?
  • Is there any good documentation/checklists/guidelines around which covers all Office 365 services? Most documentation I found are focussing on Email, or OneDrive. I have not found anything useful on Teams. 
  • What commercial tools should I look at? I have (good) experience with BitTitan, though that was a smaller migration and it was affordable. Pricing is based on user and amount of data, but I do not even know yet what I am facing (hence the inventory question). Perhaps there are other options I should consider?

Any pointer is more than welcome.

Over the last five years, I managed several Office 365 tenants, using the respective Admin Centers or sometimes Powershell. But I have never attempted such a big migration so far. 


I do have my first session with the client the day after tomorrow. At least I would like to have a rough idea what I need to look at on this current tenant. 


Thanks a lot





3 Replies
Hi Dan,
BitTitan and Quest both offer options to migrate Teams from one tenant to another.
BitTitan has a custom discovery script to help you discover content. Tony Redmond has also created a Teams discovery script which is helpful to identify active Teams versus inactive ones.
I just finished performing a similar discovery effort for a customer and it took 60 days to complete full discovery because they had PowerBI, Flows, and Microsoft Dynamics, not to mention Teams, OneDrive, SharePoint, and Identities to consider.
Hope this helps.

Hi @Joe Stocker ,

Thanks for the pointers. I will have a look.

Did you perform the discovery only with those tools?

Office 365 can be overwhelming, even for me doing Administration since years. In that new clients tenant, nobody ever thought about restricting the use of O365 Apps, tools, functions or even considered security groups and such. So there's a lot of "let's try this nice App and then forget about it again". That leaves stuff laying around. 

Migrating that chaos as such is not advisable. I told the client, but he does not (yet) realize what a migration to a new tenant will require.  To say the truth, realistically, me neither...



Hi Daniel,
No, those tools were just some of what we used to perform full discovery. Here is full list of the various administration portals to investigate, which will then lead you into deeper discovery.
1. Security and Compliance Center http://protection.office.com
Note: The Security and Compliance Center will be going away eventually and replaced with these two new portals which do not yet have 100% of the content from the combined portal
a. Security Center http://security.microsoft.com
b. Compliance Center http://compliance.microsoft.com
2. Old O365 Portal: http://portal.office.com
3. New O365 Portal: http://admin.microsoft.com
4. Exchange Online Control Panel http://outlook.com/ecp
5. Other Portals SharePoint, Yammer, Teams, Dynamics, PowerBI, PowerApps, OneDrive, Flow can be accessed from https://admin.microsoft.com/Adminportal/Home#/alladmincenters
6. Azure Web Shell http://shell.azure.com (This is protected with the Conditional Access Policy that I referenced in our meeting).
7. Azure Portal - https://portal.azure.com
8. Azure AD Portal – https://aad.portal.azure.com
9. Device Management Portal (Intune) – https://Endpoint.microsoft.com
10. Microsoft Cloud App Security (MCAS) - https://portal.cloudappsecurity.com/
11. Microsoft Defender Security Center - https://securitycenter.windows.com/
12. Azure Threat Protection Portal - https://portal.atp.azure.com