We recently posted the following message in the Message Center (which you can also see in the Tenant Status blade on the Service Health tab in Intune). If you use Apple School Manager, Apple Business Manager, Apple Volume Purchase Program or the Device Enrollment Program, you'll want to accept Apple's new Terms and Conditions. If you've got any questions on this change, we can try to help, or contact Apple for assistance.
MC197208 - Support Tip: Accept Apple’s new T&C to ensure Intune can communicate with Apple as expected
Apple is currently rolling out new Terms and Conditions (T&C). An IT admin will need to accept these new terms when using Apple School Manager, Apple Business Manager, Apple Volume Purchasing Program, and the Device Enrollment Program to ensure that the managed devices can continue communicating with Microsoft Intune, or any other MDM provider.
How does this affect me?
This will only affect you if you have MDM-managed devices and use Apple School Manager, Apple Business Manager, Device Enrollment Program, or Apple’s Volume Purchasing Program. Managed devices will not be able to sync with Intune until the new Apple T&C terms are accepted. The Intune service receives the error – “T_C_NOT_Signed” from Apple. You may be running into this error or you may soon run into the error as Apple rolls out the new T&C.
What action do I need to take?
If you use any of the listed programs, simply login to the appropriate url highlighted in the support article from Apple here: https://support.apple.com/HT203063. Once you’ve logged in and accepted the new T&C, managed Apple devices will once again be able to communicate with Apple’s device management servers.