Q: IPHONE 4s call failed??!!!

Yes I'm on Vodafone in the UK and get the same "call failed" issue on about 25% of calls. Its a company phone and my colleagues have the same issue.

Not sure if its just a coincidence but "upgrading" to the latest OS seemed to make it worse.

Another issue I have... if the initial call fails and I don't try to make the call again when I come back to use the phone after some time as soon as I unlock the phone it starts making the call again.

It's not a joke, I restored the phone, did everything I read here and the only thing that works is playing with some settings....it's the IIphone itself that has problem and Apple should fix it instead of balming the carrier, etc...

I did and it worked....but then again last time I played with different settings and it worked as well. No logical reason but thanks anyway!

Check with Vodafone.  I believe there is a new Carrier Update available.

Unfortunatly I live in Mexico and my Carrier is Telcel...we are always a fews years behind you guys! I went to the customer service and they looked at me like I was weird and tried to sell me another phone, jaja

thanks.obrigado scott

THANK YOU, YOU SAVED MY ENTIRE PHONE!!!!!!!! All day i tried everything.