As of today 1st March 2026 Microsoft is officially enforcing restrictions on the number of applications used to process data through API requests for the same task. This limitation states that you can no longer use processes to circumvent Microsoft API limitations in any way, including the use of multiple applications for parallel processing. This is most clearly stated in Microsoft Terms of Use section 3.7.
7. Attempt to circumvent the limitations Microsoft sets on your use of the Microsoft APIs. Microsoft sets and enforces limits on your use of the Microsoft APIs (e.g., limiting the number of API requests that you may make or the number of users you may serve), in its sole discretion;
This Veeam KB https://www.veeam.com/kb4821 covers this in more detail.
If you are using multiple Application then you can remove the extra applications following the steps in the below link.
Updating Certificates and Removing Applications - Veeam Backup for Microsoft 365 User Guide
Important updates from the KB are below.
How is Veeam addressing this change?
- Veeam is making improvements to reduce the number of API calls required for backups, which will help improve backup performance.
- For customers operating self-managed backups using Veeam Backup for Microsoft 365, we strongly encourage installing the latest version. Each new release includes improvements that enhance backup performance.
A new Veeam Backup for Microsoft 365 version will be released soon, and all customers are encouraged to update as soon as it is released. - For Veeam Data Cloud for Microsoft 365 users, the latest updates are always automatically deployed as soon as they are available.