Obtaining up-to-date list of US ZIP Codes with Latitude and Longitude Geocodes?
NOTE: This began as a question on Stack Overflow, which has subsequently been closed. I also noticed a similar question about Most Up-To-Date Source for US Zip Code Boundaries, but I believe this question is different in that I'm not looking for boundaries as much as I'm looking for coordinates. Sorry for new newbie question. I'm not sure where to look to find reliable and up-to-date data.
We have a table in our database that has latitude and longitude geocode coordinates paired with US zip codes. A sample of the data looks like this:
Zip State Latitude Longitude 30000 GA 33.906553 -84.206311 30001 GA 33.810659 -84.607964 30002 GA 33.77429 -84.260712 30003 GA 33.906553 -84.206311 30004 GA 34.113832 -84.294578 30005 GA 34.079927 -84.221166 30006 GA 33.906553 -84.206311 30007 GA 33.968777 -84.43282 30008 GA 33.902022 -84.580318 30009 GA 33.906553 -84.206311
The problem is that our data hasn't been updated for a few years.
Where can I obtain (for free or for purchase) updated data for this table?
ZIP codes are a habitually abused geography. It's understandable that people want to use them because they are so visible and well-known but they aren't well suited to any use outside the USPS. ZIP codes aren't associated with polygons, they are associated with carrier routes and the USPS doesn't like to share those. Some ZIP codes are points e.g. a ZIP code may be associated with a post office, a university or a large corporate complex. They are used to deliver mail.
The Census Bureau creates ZIP Code Tabulation Areas (ZCTA) based on their address database. If it's appropriate to your work you could try taking the centroid of the ZCTAs. ZCTA Geography from the 2010 Census is available on the Census Bureau website.
See also: ZIP Code Geography and Mapping
Thanks for your well-explained answer. It's clear that ZIP codes are abused, but that's what the business is using so I don't have much choice for this particular application, unfortunately. I'll pay attention to the census data for future updates.
ZCTA for 2010 TIGER are now available ftp://ftp2.census.gov/geo/tiger/TIGER2010/ZCTA5/2010/
@Sean, but even the Census says the ZCTA don't match the USPS true boundary, it is just the tabulation block they use. Yes, it is the most recent free source, but you need to take that caveat into consideration.
@D.E.Wright, yes, that's why they're called ZIP Code Tabulation Areas. There is no USPS true boundary.
Dead link in the original answer. Looks like the current URL is https://www.census.gov/geo/maps-data/data/zcta_rel_download.html.