It depends on the application that you are working on. The more you rely on geographic information the more strict you must be. So let's review why you need al

It depends on the application that you are working on. The more you rely on geographic information the more strict you must be. So let's review why you need all that info. If you don't include the zipcode with all the rest of your information, you run into the Washington Township problem. http://en.wikipedia.org/wiki/Washington_Township http://en.wikipedia.org/wiki/Washington_Township You can't infer (reliably) your exact location from a zipcode because of the reasons listed in the other comments linked to your parent comment.