I am amazed at the OP! Just search google for zip code database. The first result is the link from parent post that gives you a free list of all zip codes, and

I am amazed at the OP! Just search google for zip code database. The first result is the link from parent post that gives you a free list of all zip codes, and primary cities they are associated with, plus a ton of other data. How on earth did this even get to a freedom of information request? And how did this end up on the front page of HN?