If i don't use any data on my iphone do i still have to pay for it monthly?

I want to get a iphone for my next upgrade and wondering if i pay for it but don't use it will it roll over to the next month? I have att

Data usage DOES NOT rolloever… LOL

and if you use 0% of it, you still have to pay for it

ATT only rolls over unused minutes.

no one on earth rolls over texts and data usage.lol

Of course you pay for it per month. Meter resets monthly.

You might not be able to get an iPhone without a data plan, these days.