When you apply for this entitlement at https://developer.apple.com/contact/request/notification-service if you are subsequently granted the entitlement, you will receive the necessary documentation on how to filter the incoming notifications. Hi! I haven't received this documentation ( If you receive this documentation please share with me! Here's what information I got in response to the request: Hi,  I've received confirmation that this has been processed. You'll need to switch to manually generating provisioning profiles, as this is a special entitlement.  When you create a Development or Distribution provisioning profile for your Bundle ID, you'll be prompted to select additional entitlements. Click Profiles on the sidebar, then click the Add button (+) in the upper-left corner. Choose a provisioning profile type and follow the prompts until you see “Additional Entitlements.” Select “NSE Filtering” from the dropdown to include the Notifications Service Extension Filtering entitlement in your new profile. Click Continue to finish the process. Once your profile has been created, you'll need to configure your Xcode project for manual code signing. If your Xcode project doesn't already have an entitlements file, create a new property list file and change its extension from .plist to .entitlements. Add the keys and values of the entitlements used in your project to the .entitlements file, then follow the rest of the Xcode manual signing process. (Note that the unrestricted-voip entitlement applies to the NSE target, not the app target.) For troubleshooting, see Technote 2415 “Entitlements Troubleshooting” and Debugging Entitlement Issues. If you need additional support, visit the Apple Developer Forums or submit a Technical Support Incident.

I have the same problem, I noticed that the extension also stops working after updating the application and starts working again after a long time (it can be 10-20 hours) or immediately after rebooting the device. @tanay_phoneic did you find a solution to this problem?