There has always (since the late 90s) been a free look up webpage:
https://tools.usps.com/zip-code-lookup.htm
The data used to be available on CDROM (back in the 90s) but moved to an API in the early 2000s. Until August 2026, you used to be able to look up addresses for free.
To get the biggest discount on postage (one place I worked at mailed about 3k envelopes per month) you have ZIP+4, to pre-sort the mail and print a bunch of stuff on that barcode [0]. Next time you get an envelope, look at the barcode on the bottom.
https://en.wikipedia.org/wiki/Intelligent_Mail_barcode
0 - doing it that way saved about $450/month versus not doing any of their work for them.
Through folding: ounces flat in a 9x12 is $1.98; folded in a #10 it's $1.11. Square envelopes pay $0.49 extra.
Print package labels online: a 12 oz package coast to coast is $13.65 at the counter, $8.95 through USPS's free Click-N-Ship.
Keep boxes at or under 12x12x12. Since July, anything bigger is billed at volume ÷ 139 pounds if that exceeds its weight.
I've been building an (unofficial) searchable reference to USPS's rules and prices. The presort page is here: https://postalref.com/guides/presort
What was the reason for the 2026 change to make it non-free? Some "government should be run like a business" (and therefore charge for services) BS, or was there some kind of abuse or privacy issues they were trying to limit?
All governments provide some services for "free" and charge for others. Sometimes it makes sense, other times it really is BS.
They spun it as supporting the new RestAPI based system they put in place, it does have more efficient rate limiting, and some controls like Mailer ID verification (able to tie who makes a request for a label to that actual label, etc.) that are supposed to help with fraud.
This isn't the USPS charging for existing data. They created a new data set that's only relevant to data brokers, and are charging for it.
this in itself is quite unusual/seem kinda not clever
because now you are exposing a "implementation detail" about how you deliver the mail now to people in a way which is hard to change (or at least high friction for the people living there). But you should be able to change your postal routs ad-hoc whenever needed.
At the same time you lose many of the "dual-use" benefits many other countries get from it.
Like often (outside of the US) "zip" codes:
- are used for mail disambiguation (in combination with city/region and street names)
- cover (very very very roughly) a similar amount of people
- hence can be used for polls, statistics etc. etc.
- and due to not being to narrow scoped disclosing your zip code doesn't feel like major privacy invasion, so you actually get data for polls where e.g. your customers are from by asking at the checkout if they are willing to tell you their zip code
- are often also used for all kinds of administrative area scoping (not all, e.g. not voting areas or zoning laws)
so the us using a collection of postal routs which kinda somewhat but not maps to boundary lines seem like a major lost opportunity
Census tracts are, but those don't align to addresses in any meaningful way.
How are we to improve our Zones if the Zone Improvement Plan (ZIP) Code is not readily available?