A surcharge is used when your state, county or city requires you to tax at a specific amount for the first, so many dollars, and than tax at another rate for all money over that amount.
This screen allows you to do just that! If you have taxes set up in the rolodex file for each customer and you have surcharge amounts in the above screen, the system will automatically tax at those rates. The taxes and the surcharge are on seperate lines showing the amount that is taxed as well as the percentage that is being used.