>We are a manufacturer and have distributors (which we own) and salesmen (which deliver product) in about a dozen states. One of those states is New York where if you are in NY City (or surrounding area denoted by a list of 100+ zip codes) there is an additional tax. In Florida it seems to go by county, In PA it goes by City (Philadelphia, Harrisburg).

Ah, yeah, I know both NYC and FL have weird issues (NYC - different burroughs, same zipcode can have diff. tax, FL - county tax + a cap on the tax for any single item on the invoice).