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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?

closed as too broad by PolyGeo Jul 18 '17 at 22:56

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

11 Answers 11

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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

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    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. – Ben McCormack Jan 13 '11 at 18:16
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    ZCTA for 2010 TIGER are now available ftp2.census.gov/geo/tiger/TIGER2010/ZCTA5/2010 – Sean May 18 '11 at 15:29
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    @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 Aug 3 '11 at 1:00
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    @D.E.Wright, yes, that's why they're called ZIP Code Tabulation Areas. There is no USPS true boundary. – Sean Aug 3 '11 at 14:41
  • Dead link in the original answer. Looks like the current URL is census.gov/geo/maps-data/data/zcta_rel_download.html. – Andrew Janke Apr 3 '17 at 13:23
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Try this: http://download.geonames.org/export/zip/

It is licensed under a Creative Commons Attribution 3.0 License. They even have zip codes of various other countries around the world.

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    I checked a few zip codes that were added last year, e.g. 32461, and the US.zip database includes them, so this resource seems to be up to date. – isapir May 24 '17 at 20:18
  • These are likely ZCTA (see geonames.org/postal-codes-sources.html) – Momer Oct 13 '17 at 21:08
  • They are not only ZCTA. There are 41466 zip codes, including ones that are not ZCTA (for example, 80201). – tee Oct 18 '18 at 3:05
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http://www.census.gov/tiger/tms/gazetteer/zips.txt

We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.

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The USPS offers this service...they should be the authority. (Although even their data seems to be compiled from a variety of sources, including but not limited to US Census...)

http://www.unitedstateszipcodes.org/zip-code-database/

They just provide a latlong (presumably a centroid) but one could always (ab)use the google Earth API to at least get a bounding box for each,

e.g.

http://maps.google.com/maps/geo?q=13357&output=xml

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    The unitedstateszipcodes.org data set is third-party, not affiliated with the USPS in any way. That's why "their data" comes from multiple sources. – Matt Ball Apr 16 '14 at 14:40
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One thing not mentioned, but very important, is that the Census data is not a complete list of all ZIP Codes (ZCTAs). It is a list of ZCTAs that have a population, so PO Boxes, etc. are not in the data. There are about 42,000 ZIP Codes and about 33,000 ZCTAs.

For a complete file and true accuracy, you'll want to get a commercial product such as what Puddleglum mentioned.

One last thing not mentioned: all coordinates are not created equal! We've seen some very popular databases off by over 20 miles in the congested Northeast! Ask vendors to give you a sample of data in your area (not their standard demo file) and use a free product such as ArcGIS Explorer to verify (you can download a ZIP Code boundaries layer from their web server, ArcGIS Online, for free!)

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You can now get the updated 2010 data directly from the Census Bureau itself. This source has the coordinates of each ZCTA as well as some other information. It should be free/public domain.

http://www.census.gov/geo/maps-data/data/gazetteer2010.html

The ZIP Code Tabulation Area file contains data for all ZIP Code Tabulation Areas (ZCTAs) in the 50 states, the District of Columbia and Puerto Rico as of the January 1, 2010. The file is ASCII text, one line per record.

Direct link to the file: http://www.census.gov/geo/maps-data/data/docs/gazetteer/Gaz_zcta_national.zip

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Current data from the USPS can be had for a relatively low price, between $100 and $200. There are a number of vendors that are non-exclusive licensees of USPS data. A list is available here, http://ribbs.usps.gov/files/dpv/CERTIFIED_LICENSEES.TXT. DPV, Delivery Point Validation, certifies an address as deliverable, versus an address which falls within a deliverable street and address range. If an address is deliverable, a ZIP+4 is assigned as opposed to just a 5 digit ZIP. Some of the licensees of the data match the street and address range from the USPS with an external street centerline file to provide a geographic point representing a ZIP+4. This level of detail can be generalized back to the ZIP code and derive a ZIP point. Two products come to mind, ZP4 from Semaphore and ZIP*Data from Melissa Data. I think that the TIGER data from 2000 will be lacking, particularily for any new ZIP codes since then. All of the 2010 TIGER should be available by April. They are rolling states out weekly.

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Try the CivicSpace US ZIP Code Database. It's also available as a package in R, if you happen to use R.

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The US Census Bureau has Gazetteer files:

http://www.census.gov/geo/maps-data/data/gazetteer.html

For each year, there is an accompanying webpage. Select "Zip Code Tabulation Areas", and you will see a download link for a file. For example, the 2013 file is named "2013_Gaz_zcta_national.zip", which unzips into a tab-separated file. The schema for this file contains a zip code and a latitude, longitude pair, presumably the centroid of the zip code.

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[Edited 8/3/2015] Update - the free ZIP Code database I mentioned below has now moved to softwaretools.com

As others have mentioned, census zcta is slightly different than a ZIP Code (quickly illustrated here). Furthermore, the coordinates can be population center points (where people live) or geometric center points (mathmatical calc - often fall in forestry land, large lakes, etc). For geometric, you can get it for free here. For population-based, you'll need a commercial grade ZIP Code database like this one.

fyi - I'm a developer for greatdata.com

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The U.S. Gazetteer Files has a simple file for 5-digit US ZIP codes in their ZIP Code Tabulation Areas file. It has the following columns:

Column 1    GEOID       Five digit ZIP Code Tabulation Area Census Code
Column 2    ALAND       Land Area (square meters)
Column 3    AWATER      Water Area (square meters)
Column 4    ALAND_SQMI  Land Area (square miles)
Column 5    AWATER_SQMI Water Area (square miles)
Column 6    INTPTLAT    Latitude (decimal degrees)
Column 7    INTPTLONG   Longitude (decimal degrees)

The file for 2016 can be found at: https://www.census.gov/geo/maps-data/data/gazetteer2016.html

I imagine that link will eventually go out of date, but hopefully searching for "ZIP Code Tabulation Areas Gazetteer File" on the US Census Bureau website will yield good results even in the future.

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