Set up a mobile device management (MDM) solution and assign devices in Apple School Manager
You can manage your Apple customer number and Reseller IDs by adding or deleting supplier information as necessary. For example, a large institution may have more than one Apple customer number. If you don’t add these during enrollment, you can add them at any time.
If you purchase devices through participating Apple Authorized Resellers or carriers, you must complete all three steps below so orders placed with that reseller or carrier will appear in Apple School Manager:
Communicate your Organization ID to the participating Apple Authorized Reseller or carrier and verify that they received it.
Add the Reseller ID of your participating Apple Authorized Reseller or carrier to your supplier list.
Arrange with your participating Apple Authorized Reseller or carrier to have them submit your orders to Apple through their portal (it won’t happen automatically).
Important: If you don’t know the Reseller ID of your participating Apple Authorized Reseller or carrier, contact them for assistance.
Use Setup Assistant to enter your device purchase information
In Apple School Manager
, click Add 
next to Add Institution Details, then select Find Devices.Choose one of the following:
Enter Apple customer number
Enter Reseller ID
Enter the appropriate information, then click Continue.
If you provided an Apple customer number, Apple will verify that it matches your institution, and then post your devices to Apple School Manager.