RSS Feed

The Design of Software (CLOSED)

I'm looking for a web service that I can call with a street address, city and state and which will return a zip code.  Also, given a zip code, one which will return a city & state.

Anything like this out there, hopefully free or reasonably priced?  What about databases online or on CD-ROM that I could obtain?

I found a web service that does a bulk dump of zip code/city listings, and USPS sells a CD with a zip code viewer (but the data is encrypted).  But no going from street address to zip code.  Must be something out there...

Thanks

I believe that the USPS publishes a free database for this purpose.  We've used it in the past but switched to MapInfo because we also had to do some geospatial stuff.  I think you  can download their data file from usps.gov

It looks like the post office still has their zip+4 web service available, although hard to find:
http://www.usps.com/webtools/address.htm
http://www.usps.com/webtools/technical.htm

Sweet.  That looks like it will do.

I used to do this long ago with Census DIME files. It looks like they've renamed them to TIGER, but they're still around, and freely downloadable.

http://www.census.gov/geo/www/tiger/

You may want to chat with the developer of this site:

www.myzmanim.com

He does unbelievable geographic lookups.

I didn't realize TIGER had zip codes.  I'll have to check into it.

When I get done with this part I'm going to add a lat/lon lookup and Google Maps integration.  This is for a hobby project, and I'm kind of excited about it.

Just FYI - The USPS WebTools links probably won't do you any good. They're supposed to be used for shipping, and not for address/zip code validation. The USPS won't give authorization just for validation purposes.

I have several apps that record client information, and we're always having problems with invalid zip codes. I tried to use the USPS data via their webtools, but (even though I'm with a state government) they wouldn't let me; they sent me the link to their purchasable subscription database.

Ken

You can only use the USPS Web Tools address and zip code validation service in the context of shipping a package through USPS Web Tools.

You can also use the Yahoo! Maps geocoding API.  It will give you both scenarios you are looking for:

 IN: zip
 OUT: city/state

 IN: address, city, state
 OUT: zip+4

Note, it's free, but according to their documentation, it's limited to 5000 calls per day per IP. 

Search on Yahoo for "geocoding api" or go to this link.

  http://developer.yahoo.com/maps/rest/V1/geocode.html

Google also probably has something similar, but I know the Yahoo one works from experience. 

Also, this may not matter to your project, but zip codes sometimes map to multiple towns/cities.  This can get some customers up in arms when they type in a zip code and your application tells them they live in a neighboring city, which may have a much worse reputation than their actual city.