I am looking for Zipcode data with the +4 digits at the end for a City (I can use it by state and clip the points to my municipal boundary), and with edges or geocodes. I called the post office and had no luck (national customer center in Memphis, TN- claimed that their +4 ZIP Code GIS Layer is not for the public).
Would anyone know where I could find this data?
Best Answer
Some background: The USPS maintains zip codes as sets of delivery zones(5 digit) and routes(+4 digits), usually along streets with address boundaries. USPS does not maintain zip codes in any shape format.
I had the issue of finding a viable source as well. I narrowed my possible solutions to the following 4 and chose to go with #3.
You can download the 5 digit data from https://www.census.gov/geo/maps-data/data/tiger-line.html but the +4 data is not available from census or from the post office with +4 data.
Depending on how large your AOI is you can use the tool https://eddm.usps.com/eddm/customer/routeSearch.action to search zips. It will show the +4 routes which can be heads up digitized.
There are several companies that will sell you very accurate zip code data, Maponics being the one that I use. The five digit zip codes from them are pretty accurate. They do not offer zip+4 boundaries but they do have centroids for the +4 routes.
Your other option would be to request the address based data from USPS and attempt to create spatial data for it using parcels with addresses and streets as reference layers, though this would likely open a whole other can of worms.