How can I transfer all carrier settings from an existing phone to a new phone?
You should be able to go to settings, find your settings for you sim (APN) settings and from there be able to copy these settings to your new phone.

I am assuming your current device is an android device. On my phone (OPO5T) I can simply go to settings->Wi-Fi &amp; internet->SIM &amp; network->(My sim card)->Access Point Names.