Call failed error on iPhone after iOS 26 update

Try and force restart the iPhone to see if the issues persist

Press and quickly release the volume up button. Press and quickly release the volume down button. Press and hold the side button.When the Apple logo appears, release the side button.

If this Is not working, see if you're in need of a carrier settings update

1. Make sure that your device is connected to Wi-Fi or a cellular network.
2. Tap Settings > General > About.
3. Follow the onscreen instructions to install your carrier update.

If this is not working you might want to give this as feedback to apple, but since that you already have a case number I would presume that you have already made a ticket with apple support

Same problem here not able to use messaging and phone calls some problem with settings causes black screen freezing and crashing temporarily solved problem by resetting phone but it only lasted one day same latest update 26.01 fix problem for less than a day apple support useless try to blame phone wish i stick with 18 update

I am experiencing the same issue. The network signal appears blurred, although mobile data is functioning correctly. However, when I try to make a call, it shows “Call Failed,” and I am unable to receive any incoming calls. This problem is quite disappointing and needs urgent attention in iOS 26.

Did everything I found online including reinstalling the iOS and updating to iOS 26.0.1 but still can't make calls on my iphone 15 pro max