Support Statement — Microsoft 365 Changes to Throttling Enforcement

What's behind this change?

Microsoft imposes connection limits per application within a tenant, based on the number of licenses. Functionally, each application registration has its own threshold before throttling kicks in. Once that limit is reached, Microsoft services such as SharePoint Online will return HTTP status code 429 ("Too many requests") or 503 ("Server Too Busy"), and the requests will fail. When this occurs, the application must wait before new requests can be made, slowing backups. To work around this and improve backup performance, many backup vendors have suggested deploying multiple applications.

However, according to Microsoft's terms of use and product documentation, creating separate application registrations when those applications essentially perform the same operations, such as backup, is not permitted. As of March 1st, 2026, Microsoft will enforce those terms of use for everyone who has configured multiple application registrations. It is important to note that this is not specific to Veeam's products; it affects all third-party backup vendors that use multiple application registrations to optimize backup performance.

What action should Veeam customers take?

There is no need for immediate action, as Microsoft will enforce throttling as documented. App registration limits are applied based on their usage terms, so only one application should be deployed per use case, and multiple applications running on the same tenant share the same resource bucket. However, if your environment uses multiple backup application registrations, backups may take longer to complete.

Which tenants/organizations are impacted?

Note: Only a small portion of Veeam Backup for Microsoft 365 and Veeam Data Cloud for Microsoft 365 customers use multiple application registrations. If you are not using multiple application registrations, you will not be impacted.

While terms of use apply to all customers, those who use multiple backup application registrations for Veeam’s backup solutions for Microsoft 365 may experience throttling, as Microsoft now throttles connections across similar applications within an organization.

• Veeam Data Cloud for Microsoft 365
  Note: It was uncommon for Veeam Data Cloud customers to have multiple backup applications deployed.
  No action is required from Veeam Data Cloud customers, as any extra backup applications created for the few customers who had them will be automatically removed.

How is Veeam addressing this change?

Veeam is making improvements to reduce the number of API calls required for backups, which will improve backup performance.

For customers operating self-managed backups using Veeam Backup for Microsoft 365, we strongly encourage installing the latest version. Each release includes improvements that enhance backup performance.

Veeam Backup for Microsoft 365 version 8.4 will be released soon, and all customers are encouraged to update to it as soon as possible.

For Veeam Data Cloud for Microsoft 365 customers, the latest updates are always automatically deployed as soon as they are available.