Why is Service Principal (SPN) authentication failing for SharePoint Online ?

[RahulBhagat123]

Hi Community,

I’m trying to authenticate a SharePoint Online Excel connection in Power BI Service using a Service Principal (SPN).

Here’s the background:

• In Power BI Desktop, I connected to SharePoint using the Web connector and my personal credentials.
• After publishing the report to Power BI Service (Pro-backed workspace), I tried to switch the dataset credentials to use Service Principal (SPN).
• However, the SPN authentication keeps failing, even though the “Service Principal” option appears in the dataset credential dropdown.
• The same SPN works perfectly for connecting to SharePoint Online in Azure Data Factory (ADF) using the client credentials flow (App ID + Secret).

My questions:

1. If SPN authentication works for SharePoint in ADF, why is it not supported in Power BI Service?
2. Why does Power BI Service show “Service Principal” as an option under Data source credentials if it’s not actually supported?
3. Is there any roadmap or workaround (e.g., Workspace Managed Identity) to enable SPN or similar authentication for SharePoint sources in Power BI?

Additional context:

• Workspace type: Pro (not Premium)
• Data source: SharePoint Online Excel
• Goal: Use SPN / non-interactive authentication for scheduled refresh instead of personal credentials.

Any guidance or official clarification would be greatly appreciated!

Thanks,
Rahul

[tayloramy]

Hi @RahulBhagat123, 

FOr Fabric, you need to grant permissions to the service principal using the legacy method described here:  https://learn.microsoft.com/en-us/fabric/data-factory/connector-sharepoint-online-list-copy-activity...

Once you do this, it would work. 

Note tha this auth method is only supported for dataflow Gen 2 and Copy activities: 
https://learn.microsoft.com/en-us/fabric/data-factory/connector-sharepoint-online-list

If you found this helpful, consider giving some Kudos. If I answered your question or solved your problem, mark this post as the solution.

[v-veshwara-msft]

Hi @RahulBhagat123 ,

Thanks for reaching out to Microsoft Fabric Community.

Currently, Service Principal (SPN) authentication is not supported for SharePoint Online Excel or Folder connections in Power BI Service. Although the “Service Principal” option appears in the dataset credential dropdown, it is functional only for SharePoint Lists. This is why the same SPN works in Azure Data Factory, where SharePoint supports the OAuth 2.0 client credentials flow, but fails in Power BI Service which still requires user-based authentication for Excel or Folder sources.

If you are looking to avoid personal credentials, a dedicated organizational account can be used for the SharePoint connection. SPN or Managed Identity-based authentication for SharePoint sources is being reviewed for future consideration.

There has also been some discussion suggesting that setting the SharePoint tenant property 'DisableCustomAppAuthentication' to false may help in some cases. The discussion is available here:
Adding a SharePoint data source with a service pri... - Microsoft Fabric Community

You can also track the related posts and ideas for updates on this topic and upvote any idea that aligns with your scenario:

Connect to Excel file in SharePoint library using Service Principal
Enable Service Principal Authentication for SharePoint Data
Developer discussion: Connect to Excel file in SharePoint library using Service Principal
Support for SharePoint folder connection using Service Principal

For now, Power BI relies on delegated user authentication for SharePoint Online connections, and SPN support for files and folders is not yet available.

Hope this helps. Please reach out for further assistance.

Thank you.

[v-veshwara-msft]

Hi @RahulBhagat123 ,
Just wanted to check if the response provided was helpful. If further assistance is needed, please reach out.
Thank you.