I've only had to use AC once. I called the AC number and they took it from there.
In my case, they assigned an ASP to my issue and had someone travel 60km to my flat for an on-site repair (iMac hard drive).
In your case, if it is only a cracked screen and due to drop or other 'caused by the user' incident, it might not be covered under regular AC. If you have AC+ it might be different.
I'm out of touch with AC policies at present as the most recent iPhone we currently have is an iPhone 6.
I have AC+ through the iPhone upgrade program, so my understanding is that I'll have to pay something, but it'll be more like £30, as opposed to £280 without any AC.
Comments
In my case, they assigned an ASP to my issue and had someone travel 60km to my flat for an on-site repair (iMac hard drive).
In your case, if it is only a cracked screen and due to drop or other 'caused by the user' incident, it might not be covered under regular AC. If you have AC+ it might be different.
I'm out of touch with AC policies at present as the most recent iPhone we currently have is an iPhone 6.
https://support.apple.com/iphone/repair/service/screen-replacement