The City of Amarillo Rolls Out The Utility Billing Mobile Unit At least mine did. The city announced today that they are rolling out (no pun intended) the Utility Billing Mobile Unit. It's exactly what it sounds like. Get our free mobile app Instead of the awe and wonder of children's books, this mobile unit will be bringing you the opportunity to pay bills. Yay. The Utility Billing Mobile Unit is outfitted with a drive-thru window and a couple of walk-up windows. It also doesn't look like a painted over Winnebago. It's more like a food truck, without the truck part.