Phone calls on an iPad

I have an iPad Air, which has been upgraded to iOS 8.1. I understand that I can use my Vodaphone SIM to make calls and send texts on the iPad now. How are they charged? Does it just use up some of my data allowance? Martine Hatton iPads can’t do these things directly. Cellular models only use the mobile network to get online. You may be thinking of a Continuity feature in iOS 8 and OS X Yosemite, which routes calls (and with iOS 8.1, texts too) through an iPhone. Both devices must be signed in to the same iCloud account and be connected to the same Wi-Fi network. Charges come out of the iPhone’s plan.