My wife and I have two new iPhone 6's. Whenever one of them rings the other one rings also. I've been back to Best Buy (where purchased) and the local Verizon store. they both made changes to our phones, then called each one separately and it seemed to be fixed. However, when we got home the same problem exists. It's driving us (me especially) crazy. What can we do to fix this problem?
You are sharing the same AppleID for your iCloud account.
1. (Preferred) set up separate AppleID for each phone. You can still link them with Family Sharing.
2. On phone, go to Settings/FaceTime and turn off iPhone cellular calls
If you're sharing the same Apple ID that is probably why it is doing that. Go in to the settings on both devices and make sure you only have your phone number checked for caller ID under FaceTime and the only methods you have to be reached is your phone number...if you both have the Apple ID email address then you both will ring when a call (I believe from another iPhone) comes through.
Another option is to just turn off the "iPhone Cellular Calls" option under FaceTime. This allows other devices that share your Apple ID to ring when a call is received. It was intended to be for those who have iPads and MacBooks that would like to be able to answer their phone when they are close by without having to get off of that device to go actually answer their phone (if that makes sense). But...it could also cause another iPhone to ring if it's sharing the same ID.