We'd suggest contacting your state department of revenue to request a list of ZIP codes and their effective total tax rates. If you can provide that list to us, we have a way of distilling that down to a minimal list of tax-rate rules for partial and whole ZIP codes to paste into our Advanced Tax Settings. We actually did this for a seller in NY just over a year ago, but I don't know if the rates may have changed again since then, so it would be advisable to have us regenerate this list for you.