I have the ATT unlimited texting plan. My friend has the Verizon unlimited plan and her parents recently got hit with a CRAZY bill because we texted all the time. The reason this happened is because we're on different networks. My parents are freaking out that ATT has extra cost for texting out of network too. I think that on ATT you can text anyone, but my parents think otherwise. So who is right?

I already checked att.com, but couldn't seem to find anything. I do text A LOT. Like at least 150-200 a day.