Deleted or Canceled Subscriptions and Add-ons
"Change Reseller MPN ID" is not applied to Deleted or Cancelled subscriptions and add-ons, since the status of the respected subscription/add-on is retrieved from the BSS.

Failed Subscriptions
Failed subscriptions with external id are affected by the update whereas failed subscriptions without external id, are not affected.

Invalid Reseller Account ID - Continued
During the validation procedure, we mentioned the "Invalid Reseller Account ID" error message. However, you also need to be mindful of the following issues.

When a Reseller's Account ID is also a Tenant Reseller Account, and you try to change the reseller's MPN ID then an error appears claiming that this is not a valid BSS reseller.
If you provide a valid Account ID but from a different organization, the tool will not be able to complete the update process successfully.

Trial Subscriptions
The "Change Reseller MPN ID" tool acts on trial subscriptions in the same way as in normal subscriptions. The tool will check the "From MPN ID and if it matches with a trial subscription on the Microsoft Partner Center side, it will modify the trial subscription and replace the "From MPN ID" with the "To MPN ID" at Microsoft Partner Center.

Browser not supported