Microsoft will introduce stricter enforcement of throttling rules for Microsoft 365 backup applications starting March 1, 2026. These adjustments affect how backup solutions interact with SharePoint Online, OneDrive for Business, and indirectly Microsoft Teams data. They eliminate the long-standing workaround of deploying multiple application registrations to improve performance.
Summary
- Stricter Microsoft 365 throttling enforcement begins March 1, 2026
- Multiple application registrations used for backup will no longer provide performance improvements
- Tenants with several registrations may experience slower SharePoint, OneDrive and Teams backup throughput
- Backup vendors are updating their products to reduce Microsoft Graph API consumption
- Organizations should review and remove unnecessary registrations in Microsoft Entra ID
The changes apply to all third-party backup vendors using Microsoft Graph and SharePoint APIs for Microsoft 365 backup operations.
This article summarizes what is changing, why it matters, and how organizations should react now.
What is changing?
Microsoft is updating how throttling is applied for applications accessing SharePoint Online and OneDrive for Business. Each backup application registration in a tenant is subject to connection limits. Once these limits are reached, Microsoft services respond with:
- HTTP 429 (Too many requests)
- HTTP 503 (Server Too Busy)
Backup applications must then delay additional operations, leading to elongated backup windows.
In the past, some vendors recommended using multiple app registrations to distribute request load. However, Microsoft now has reconfirmed that creating multiple registrations that perform identical backup operations violates the Microsoft APIs Terms of Use.
Beginning March 1, 2026:
- Microsoft will actively enforce these guidelines
- Similar backup applications will be throttled as a single workload
- Multiple app registrations will not bypass throttling
- Performance may decrease in tenants relying on this workaround
The enforcement applies to all backup solutions accessing Microsoft 365 APIs and is not limited to a specific vendor.
Why is Microsoft tightening throttling?
Microsoft Graph and SharePoint Online APIs must remain stable and responsive for all customers. Multi registration backup strategies place uneven load on API endpoints and contradict the responsibility-based throttling model described in Microsoft’s documentation.
By enforcing the rules consistently:
- Microsoft ensures equal resource access for all tenants
- Backup operations become more predictable and transparent
- Vendors are encouraged to optimize API consumption rather than work around platform limits
Impact on Backup Solutions (General Perspective)
Most organizations use Microsoft 365 backup products that operate within a single application registration. These environments will see no change in performance.
However, organizations that intentionally deployed multiple registrations to increase throughput may observe slower backup cycles once Microsoft begins unified throttling. This may affect:
- Backup duration
- Incremental sync cycles
- Recovery point objectives (RPO)
- Daily scheduling and maintenance windows
Backup vendors are actively improving efficiency to reduce dependency on high numbers of API calls.
Example: Veeam Backup for Microsoft 365
Veeam Backup for Microsoft 365 is one commonly used solution affected by these policy changes.
How Veeam customers may be impacted
- Most Veeam customers use a single app registration and will not be affected
- Customers who created multiple backup applications to distribute load may see slower backups
- Veeam is releasing a new version for Veeam Backup for Microsoft 365 with significantly reduced API usage to help maintain performance
- Veeam Data Cloud for Microsoft 365 customers are automatically updated and require no action
How to Check and Remove Extra Backup Application Registrations
Prerequisites
To manage or delete application registrations, you need:
- An application registered in your Microsoft Entra ID tenant
- At least the Cloud Application Administrator role
- Access to the tenant where the application was created
Application registrations consist of two components:
- Application Object: The app itself (its settings and identity) (exists only in the home tenant)
- Service Principal Object: the app’s active instance inside your tenant
If you delete an app you created, both the application object and its service principal are removed.
If the app is multitenant (for example from a vendor), only the service principal in your tenant is deleted.
How to Remove Backup Application Registrations in Microsoft Entra ID
Follow these steps to remove unnecessary backup app registrations:
- Sign in to the Microsoft Entra admin center with Cloud Application Administrator rights
- If you manage multiple tenants, use the Settings icon to switch to the correct directory
- Navigate to Entra ID > App registrations
- Select the backup application you want to remove
- Review the Overview page
- Select Delete
- Read the deletion consequences. Check the box if one appears at the bottom of the pane.
- Select Delete again to permanently remove the app
This action removes the application’s service principal from your tenant as well.
Deleting unused or non-compliant registrations ensures your backups comply with Microsoft’s new throttling rules.
What organizations should do now
- Check your Entra ID for duplicate backup app registrations
- Remove any extra or outdated registrations
- Make sure your backup solution uses only one app registration
- Watch your backup times after March 1, 2026
- Update your backup software when new versions are released
- Ensure your schedules allow for slightly longer backup cycles if needed
Looking for a better Microsoft 365 backup solution?
Contact SCHNEIDER IT MANAGEMENT to ensure your Microsoft 365 backup environment remains efficient and resilient under the new throttling rules.
Sources
Veeam article on Microsoft 365 Changes to Throttling Enforcement: https://www.veeam.com/kb4821.
Microsoft APIs Terms of use: https://learn.microsoft.com/en-us/legal/microsoft-apis/terms-of-use.
Updating Veeam certificates and removing applications: https://helpcenter.veeam.com/docs/vbo365/guide/removing_backup_applications.html?ver=8#removing-application.
Removing apps in Microsoft Entra – Microsoft Learn: https://learn.microsoft.com/en-us/entra/identity-platform/howto-remove-app.
Microsoft Entra admin center: https://entra.microsoft.com/#home.