USPS now offers official ZIP Code boundary polygons

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USPS now offers official ZIP Code boundary polygons

munro

Comments (154)

SwellJoe
Dang, the prices are crazy. $10k for the lowest tier? I expect federal data to be free. Most federal data related to stuff like regulation (e.g. FCC spectrum use coverage maps), maps for federally-managed lands, etc. is free. And, it should be free. It's a core part of accountability and transparency. Historically there was a copying cost (having a human print physical copies on paper or CD/DVD/tape), which is understandable, but now that the incremental cost of each new copy approaches $0, that's what it should cost users of the data.
xp84
This is interesting. For a long time it was pointed out that ZIP codes, unlike say, city or state boundaries, were not properly representable as polygons, since they don't divide up acreage into zones, but rather label postal delivery routes. Suppose I build a new neighborhood way out in the middle of nowhere. The "polygon" concept suggests that we could look and see what polygon I'm in, and that will determine what post office delivers my mail. But in reality, if there was no route to that area already, they could decide to make it part of any one of the surrounding routes.I suppose though, as long as you let the polygons map has uncontained areas, where no routes currently exist, it's a doable task to draw polygons around the limits of every route network, as long as you don't mind that they may have lots of weird ragged edges.
showerst
I thought these were going to be free and got so excited.FWIW if you're willing to deal with some 'fuzziness' and the occasional missing zip code that's commercial only, the ZCTA shapefiles are free and are close enough for many purposes: https://www.census.gov/programs-surveys/geography/guidance/g...
johnnyo
If this is govt-owned data, shouldn’t it be available with a FOIA request or similar?Can someone with expertise in govt data rights explain? Do any other US govt agencies sell data to the private sector?
legitster
Some important context - Zip codes were not established as geographic markets. A "Zip Code" is collection of routes USPS uses - so it's whole goal was to get the right package on the right truck.The "Zip+4" was the attempt to solve this- the 9 digit code narrows down the zipcode to a single block. But no one in the US cares enough to use these. It also doesn't solve the canonical problems the industry has with mapping data - people want to be able to put a pin in a random place on the map and pull up a clean zip code for data processing reasons.
foxfired
I feel like this should be public. I wonder what would be the repercussion of a gofundme to buy it once and make it publicly available. There aren't many downsides of updating every couple years.
toolslive
in the EU, this is considered FAIR (Findable, Accessible, Interoperable, Reusable) data. You can just find this on govt portals.
taylorfinley
I live in an agricultural area in Hawaii with large lots and crappy dirt roads. USPS do not offer mail delivery here. Because of this, my home address is listed in public databases in no fewer than 3 different zip codes. Trying to get my address identified in a product when it demands a home address is always spin of the roulette wheel as to which one (if any) will work. It would be lovely to get an official answer about which zip code my lot falls in, especially if other databases start using the definitive value!
konfusinomicon
bottom line is that this should be open source and available on the US governments dataset website.
azhenley
I wrote a JS library and blog post about mapping latitude and longitude to country, state, and city with a small, in-memory lookup. It was fun to build! My startup was paying a lot of money to Google's reverse geocoding API.Blog post: https://austinhenley.com/blog/coord2state.htmlHN discussion: https://news.ycombinator.com/item?id=44175356
grzaks
Using ZIP codes to define geographic regions is always a bad idea. A ZIP code is an address attribute, not a geographic boundary. Some ZIP codes are assigned to PO boxes or parcel lockers, while entire cities may share a single ZIP code. You can even have streets stretching 30 km across a city, all under the same ZIP code.
ortusdux
I'm sure their system has its faults, but I find shipping to the UK via postal code quite easy."A full postcode identifies a group of addresses (typically around ten) or a major delivery point."https://en.wikipedia.org/wiki/Postcodes_in_the_United_Kingdo...
jackconsidine
Seeing enterpriseWe use https://github.com/OpenDataDE/State-zip-code-GeoJSON - it's from 2010, but open it in Claude and use the free-to-download data source to regen from the most recent census.
mzagaja
As someone who has done tons of geospatial work I hate this. A ZIP code was never technically a geospatial boundary. Being "inside" a boundary does not guarantee you have that ZIP code, just that the space is surrounded by a bunch of postal delivery addresses bearing the ZIP code.
mc007
did something similar if anyone needs it, boundaries for GADM zones, fast with cache, population center, was quite a mess to get good results : https://github.com/polymech-info/gadm - easy to render in maplibre
nxobject
I'm not sure how many fields will find this useful -- other core geo/spatial datasets use the related-but-not-identical ZCTAs, especially Census demographic data. Perhaps transportation operations?
mannyv
The bummer thing about their data is it's ZIP, not ZIP+4. Technically ZIP+4 is internal to USPS because it identifies a specific route (or something like that), but it's also is more precise than ZIP.The original tiger/line or ZCTA data is probably good enough for everyone. Those are available "around." I think the census provides them. I believe the census has the zip+4, but it's been years and I might have gotten them from somewhere else.The interesting thing in the data is the ESRI feature classes. I wonder what the heck those are.
themgt
Reminds me of one of my favorite little rabbit holes, trying to find this data for Canada:Canada is one of the only major countries where the postal/zip code boundary data is not available as an open data set. Canada Post has a monopoly on that dataset. As a Canadian GIS person it drives me nuts as many other Candian government GIS programs have been active in the open data/open-source world for decades. Even crazier is that Statistics Canada has an open database of all addresses in the country here https://www.statcan.gc.ca/en/lode/databases/oda that has a postal code column, but it's empty for all addresses.Anyone who has tried to create their own dataset of polygons has usually ended up being chased down by Canada post. There is a company called Geocoder.ca who made a geocoder and when you passed in a street address with a postal code in it, it would keep track of that, and geocode based on the street address. Over time they built up a database of coordinates and postal codes and were able to generate their own approximate boundaries that where pretty accurate. Canada Post went after them: https://geocoder.ca/?sued=1 Their data is still free for non-profits, and relatively cheap for commercial purposes: https://geocoder.ca/?freedata=1 The only other open data related postal codes you will find easily available is Forward Sortation Code boundaries (FSA) which is the area that represents the first three characters of a Canadian Postal code. For example, postal code "N0R 1K0" would have an FSA of "N0R". For demo's and some analysis scenarios that can often be enough.https://learn.microsoft.com/en-us/answers/questions/1655227/...
otter-in-a-suit
This is hilarious. I was basically bullied into writing this via the GIS folks on reddit: https://skaldmaps.com/blog/2026/07/zip-codes-are-a-bad-spati...Because, well, ZIP codes aren't a spatial thing. I guess I have to update that?And the fact that this isn't free is... a decision.
fractal618
Is this more about efficiency or politics and regulation? I can’t open the technical files on my phone.At first I thought maybe this could be used to correct gerrymandering, but then I remembered all my cynical deductions.
teddyh
s/offers/sells/
kylehotchkiss
Maybe somebody should sue them into releasing a base set for free. Or maybe FOIA the files out.USPS can charge funny money for the latest version.
untessela
starting at $10k
Hnrobert42
For everyone saying it should be free, the USPS charges for services. They charge to deliver mail.Cut them some slack. They are supposed to be budget neutral. It is difficult to do when A) they have to compete with the private sector while adhering to public sector rules and B) being sabotaged by Trump's postmaster general appointee.
tomrod
This is huge!
nukanse
If the polygon delimits a property, it could be used for drone delivery
bayesnet
It's extremely disappointing that USPS has gone the way of the Ordnance Survey on this. UK postcode polygons (at the unit level) have been paywalled for some time, but its even worse in that as far as I know there's no way to even get a straight answer as to how much it will cost to get the Ordnance Survey postcode products' data.It's especially annoying in the UK case because there is such rich national data, but for so much of it the only join key is the postcode unit, which can change over time and for which no public polygon is available. Evidently the Ordnance Survey doesn't even keep historic vintages of its releases...
Joker_vD
...Can someone please explain why ZIP codes are even a thing people need to bother about? Like, there's an address on the letter/parcel — that should be enough for the USPS to deliver it, right? If they use some internal classification/address grouping for better routing — fine, whatever, they can use it but surely they themselves can look it up in their internal DB quicker and more reliably than I can on some random web-site of dubious progenity?
tjwebbnorfolk
Even if I wanted to buy this data, I can't figure out how
CrzyLngPwd
Welcome to the 21st century
VLM
Its heavily regulated to be a universal service.Its funded with the expectation of hypercapitalist efficiency.Somehow they actually run a profit off delivering junk mail annually, but they also have amortized expenses such as pensions etc which are sinking them. Again as per above, as a hyper regulated universal service they can't declare bankruptcy, while at the same time they're hypercapitalist and somehow have to make due as the financials sink lower and lower.Some say this is an intentional plan to destroy the postal system. You can't run on a political platform of destroying the office, it would be very unpopular to propose everyone pay more for for-profit mail delivery and did I mention who one of my corporate campaign donors is? but you can intentionally sabotage the USPS by always making the worst choice at every decision intentionally, and then "unavoidably we have to shut the service down for no known clear reason it just doesn't work". My guess is the intentional destruction will continue unabated until closure is announced.Its currently illegal for private carriers to deliver normal non-urgent letters because the USPS is a monopoly. You can put a document in an envelope or small box and UPS it, but its technically quite illegal at the federal level. My guess is eventually UPS or Amazon or fedex will purchase a law to be able to sell normal ground service physical first class mail delivery. I'm betting on Amazon winning a contract for this.My bills are all emails lost in my spam folder and I "just know" to visit my car insurance website and electric company website every month or so.Its worth considering that junk mail delivery is hyper profitable for the USPS, so thats probably not going away when mail delivery gets privatized. What is going away is the 82 cent postage stamp. UPS ground saver is a couple bucks. It'll be cheaper to take a picture of a letter then order prints of the picture at Walgreens nearby my mother than to mail her a greeting card LOL. Walgreens charges 39 cents for a post card sized digital print and their letter size prints are a ripoff at $4.50, better off sending multiple post card sized prints.
1-6
Webapp in 3.2.1...
ProblemExplorer
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billbuild
This is amazing! It's actually how many people think spatially, who are not involved in politics versus congressional districts and census tracts.
readthenotes1
The USPS is losing money hand over fist delivering the unwanted junk mail and Christmas cards we throw away once the tree is put away.I don't think this will stop the bleed, but maybe it'll help that they are charging??
whalesalad
of course they are going to try and monetize this. that's trump's america.