Will using my iPhone's hotspot cost extra money?

I have an iPhone 4s (which is up to date on all IOS updates) and I have the unlimited data plan at AT&T. I'm leaving for a road trip tomorrow, and I wanted to turn the hotspot on so I could use that Wi-Fi on my laptop during the trip so I won't get bored. It says I need to set up an account for it, which I will do later… But would any extra charges be added to my bill?

I'm almost positive it doesn't. My mom has an iPhone 4s also and she lets my sister and I use her hotspot when we go on roadtrips. She is really frugal and I doubt she would let us use it if it costed extra money xD Maybe look it up on the apple website. Hope I helped!

I would talk to AT&T just to be safe. I don't know how AT&T's plan for you but I don't think it will charge your hotspot since you mentioned that you're on a unlimited plan. For my carrier, they charge me if i'm out of my carrier's range area. (like if i'm in another country)

You're currently on Unlimited data; Tethering/mobile hotspot is not offered with your data plan. There are a few options that will give you hotspot included at no charge: 5GB of data for $50 OR AT&T Mobile Share plans. Either way, it would require that you forfeit your unl.data