As I have just gotten an iPhone for the first time, (been using an android based phone) I was trying to learn if the phone had a similar feature to my android known there as "prefix dialing" whereas, you could specify a given prefix, and all manually dialed calls would use that prefix (specifically the area code) for your dialed calls.
Well, after looking into this "Dial Assist", it's just a theory, hopefully someone can validate or correct me here... wait, nope, I just tested my theory and debunked it.
I thought maybe Dial Assist, read your personal phone number (with area code) then maybe applied that code to any manually dialed call but no, that's not it either.
I found that when I manually dialed a number, somehow, the area code is applied but not shown (i.e. the AC doesn't appear in the dialed number seq.).
So I then turned off Dial Assist... but am still able to dial without manually dialing the area code.
So, the issue I initially had... isn't an issue after all, although I would like to know how to change that if I needed.
But I too, still don't know what "Dial assist" is for.
I should mention that the reason I was was looking/asking about the auto prefixing... a few years ago, due to dwindling number availability due to VoIP and number portability, AT&T made us start dialing our own area code, not to mention creating AC overlaps. As 90% of my calling is with my home area code, I wanted the "auto prefix thing" which it would appear... is mystically available already!!??!!
Would still be nice to better understand this "Dial Assist" though.
-Dave