Uh yes you do.
Now with T Mobile you were supposed to pay extra for that service but the idiots still let you turn it on and I don't believe they had any way to tell if you did or not at the time I used it. I only used it once on vacation so my wife could get internet access on her ipad while we were on the road. I didn't get charged but they may have solved that now. Anyways you were supposed to pay.
With Sprint it won't allow you to turn it on until you set it up by calling them or going to their website first. It's $30 a month so needless to say I won't pay that. We would use it maybe once a year on vacation. Someone said you could use it for $1 a day which I might if it's true.
You must be reading the same internets as Rakeesh.