Does having personal hotspot on use up data?

On iphone, does it use up any of your cellular data having the setting on even if no devices are connected to it?

It shouldn't use any but just to be safe just turn it off when not needed!

It only uses data when devices are connected to it, but if it's still on but no devices are connected it will drain your battery quickly. And watch out for people in public places that want to steal your connection, even if you have a password on it.