I have relocated my business to a state the requires that I collect sales tax based on where the order is shipped, not based on my location. There are 358 taxing districts in Washington State, any of which could possibly have a different rate. CubeCart allows me to specify sales tax rates based only on orders shipped to Washington State as a whole. I have been charging the highest rate and refunding based on the customer's actual shipping location. It's getting old, fast.
Is there a module that will allow me to further break down the rates I charge based on ZIP Code? It would be a little effort to set up, but I think it will save some headaches in the long run.