Sort of. For example, when I went to Europe in Dec 2009 I brought my AT&T phone with me but I used a calling card. I didn't incur any additional call charges on my bill. As you know, with your AT&T plan you're provided either 400, 900 or unlimited mins per month depending on the plan you choose. Then you have your roll over mins. The mins that are included in your plan and the roll over mins are the mins you're using when you dial into the 800 number for the calling card. That's much better than paying 99 cents a min. You can buy calling cards online for as little as 10 dollars with 500 mins, pinless dialing and internet recharging. You'll receive and email with the details of your calling card purchase and not a physical card. You should look into it.