A fuel surcharge is an additional fee layered onto the base rate of a load to account for changing fuel costs. Because diesel prices swing, separating this piece out lets rates stay fair to both carrier and customer as the market moves.
It’s usually spelled out on the rate confirmation and factored into the true rate per mile a load pays. When a dispatcher evaluates whether a load is worth taking, the fuel surcharge is part of the real revenue, not an afterthought.