I have 2 lines on the same account. If we have data off, how much would it cost for us to call each other.

That depends on your carrier. If they're recent iPhones on an American carrier, one option would be to buy SIM cards for the countries you visit. If you stick with your carrier and it isn't T-Mobile, it could be two or three dollars a minute.

This is an Iphone 5. I didn't see how I could remove the sim card. I will research this.

The SIM tray is on the right side of the phone. Press a small paper clip in the hole and the tray will pop out. You need to press harder than you might think.

Who is your carrier?

Att. I did find the SIM card slot. Thanks for your help.

Unless AT&T unlocks the phone for you (or you bought it full price - $600 - unlocked) you won't be able to use a different SIM in it. I went through this a little bit ago, wish I had purchased an unlocked phone.

Ok. That's the end of that. Thanks. Well
Use wifi and Skype.

Maybe not. AT&T AT&T says they'll provide an unlock code if your device is paid for in full. I understand that to mean that, if you bought it on contract, enough months have passed to cover the whole cost of the phone.

The page I linked to above has a link to AT&T's online unlock request form. It would only take you a few minutes to fill it out and see whether your phone qualifies.

Since you mention that you only want to use your iPhone's for voice calls, there is another solution:

Use your iPhone's only over wi-fi (Skype) when in a hotel room or hot spot.

Purchase 2 cheap pay-as-you-go phones once you land in Europe.

This way, you use inexpensive phone service provided by a Europe carrier for voice calls to each other and only use the iPhones where you can get free wi-fi and avoid all ATT charges for international use. Google "pay as you go phone Europe" and you'll see several choices, the easiest thing to do is grab them at a 7-11 at the airport.

BJ

Thank you, I will look into that. I also discovered that they have a 30 minutes for 30 dollars plan which would work for my situation. We would only be calling each other if we got separated and needed to find each other.

In most of Europe the going rate for AT&T is $1.50/minute, so if you call each other that will be $3.00/minute (a minute on each end). If you're really just planning on this as an emergency back-up, that's ten minutes of calls before the roaming plan makes sense. Another option is texting each other - text while roaming is something like 35 cents each. OCTeckels and I do that to coordinate when we get split up.

I know with the AT&T data roaming plans, you can backdate the start of the plan to the start of your billing period. It's possible that you can do the same with the voice roaming. You can manage this yourself on the AT&T website, and you can go all the way to picking dates and still cancel if you want to check in advance.

Do you have to use "voice"? While 30 minutes for $30 is not too bad, it does round up to one minute. That means a call to your saying "I am done shopping, you can come meet me at the Gucci store." is going to cost both you and the person calling you a minute each out of the 30. AT&T also has the 120MB data plan for $30. With iMessage at around 2Kb per message, you can send/receive 60,000 text messages. And with iMessage enabled, all your friends in any part of the world could contact you via iMessage on their iDevices. I probably wouldn't try to use Skype for 120MB though.. the video streaming will eat up the data really fast, but iMessage would be perfect. The only problem with iMessage is that if you have a lot of friends and family members who like to do group messages with pictures.... that would eat up the data really fast also.

120 MB is plenty enough for a voip/skype calls as long as you do not use video. You can make skype calls without using the video part.

Depending where you go in Europe a lot of places will unlock the phone for you for a small fee.