Microsoft has updated the authentication flow used by Excel Power Query when connecting to enterprise data sources using Organizational Accounts (Microsoft Entra ID). This change strengthens security and improves the reliability of connections to enterprise services.  

What is changing? 

Microsoft is updating the legacy authentication flow used by older versions of Excel Power Query. After the enforcement date, unsupported versions will no longer be able to authenticate supported data sources using Organizational Accounts (Microsoft Entra ID).  

Affected Power Query connectors include, but are not limited to: 

• • SharePoint (Lists, Folders, Files)  

• • SQL Server and SQL Analysis Services  

• • OData  

• • Power BI  

• • Dataflows  

• • Dataverse  

• • Azure Data Lake Gen2  

• • Azure Blob Storage  

• • Azure Data Explorer  

• • Oracle  

• • PostgreSQL  

• • Dynamics 365  

• • Web and file-based connectors (including Excel and JSON files) 

Who is affected? 

This update only affects users who: 

• • Use Excel Power Query to connect to enterprise data sources using an Organizational Account (Microsoft Entra ID).  

• • Are running Excel 2021 version 21.08 or an older build.  

Users of Microsoft 365 Apps for enterprise and newer supported versions of Excel are not affected, as these versions already use the updated authentication method. 

Required action 

If you are using Excel 2021 version 21.08, you must: 

• • Update Excel to build 16.0.14334.20754 or later by July 24, 2026, or  

• • Upgrade to a newer, supported version of Excel.  

Devices running versions of Excel earlier than version 21.08 should be upgraded to a supported release.  

What happens if no action is taken? 

After Microsoft enforces this change, users on unsupported Excel versions will no longer be able to authenticate supported data sources using Organizational Accounts (Microsoft Entra ID) through Power Query. This may prevent users from refreshing existing queries or creating new connections to enterprise data sources.  

Need help? 

If you have questions or require assistance updating Excel, please contact the Enterprise Service Centre at https://uoft.me/m365help. 

Source: Microsoft 365 Message Center, MC1403409: https://mc.merill.net/message/MC1403409

Kind regards, 

Enterprise Applications & Solutions Integration (EASI) 

Information Technology Services, University of Toronto