Free Download of the zip code CSV file available at the bottom of this post.
Why this is so hard to track down I don't know. We were looking for a comma
delimited list which would map zip code to county since county is the lowest
grain available in the out of the box SQL Server Reporting Services (SSRS) maps. There are plenty of vendors offering this data for a fee, but who wants to pay a fee for a proof of concept project? Not I. As an added bonus this free list has latitude and longitude coordinates as well.
The attached file contains the following fields:
Sample Data Format:
"91941","+32.761050","-116.998102","LA MESA","CA","SAN DIEGO","STANDARD"
Of note: We have not used the data in this file yet so I'm not sure if
there are any issues with it.
The original source of the file was the site below. In addition to providing this file they also have a Canadian Postal Code CSV and a few files mapping IP addresses to city or country.
Without further ado, here is the link to the compressed zip code file: