Search United States USA Zip Codes
Postcodez Zip Code API

The Postcodez.com API is a RESTful service that provides United States postal data and zip codes in various formats. Because the service is free and doesn't require registration, we've mitaged the potential for abuse by rate limiting unreasonable requests and we truncate various types of output.

Limitations

When searching zip codes as a distance from another zip code we'll return 100 results. If searching for zipcodes as a distance from a geographic point (lat/long) then, again, we'll limit results to 100. If you're searching multiple zip codes, we'll only accept 25 - regardless of whether they're valid or not.

Need Something More?

If you feel that our limits don't meet the needs of your service, get in touch and we'll white-list your application.

zipAPI.net

The Postcodez service is in 'beta' but will always be available and will always be free. Our full featured (registration based) API will become available at some point in the future at zipAPI.net.

API Usage

Distance Between two United States Zip Codes

http://www.postcodez.com/api/distance/<zipcode>/<zipcode>/api.xml 

Result:

Example

Search Multiple Zip Codes

The format to search mutiple Zip Codes is as follows:

http://www.postcodez.com/api/zip/<zipcode>,<zipcode>,<zipcode>/api.xml 

To retrieve details of a single Zip Code, simply use the following:

http://www.postcodez.com/api/zip/<zipcode>/api.xml 

Result:

Example

Search Zip Codes Within a Radius of Another Zip Code

http://www.postcodez.com/api/nearby/<zipcode>/<Distance><Unit>/api.xml 

Result:

Example

Search Zip Codes Within a Radius of GeoGraphic Coordinates

http://www.postcodez.com/api/geo/<latitude>/<longitude>/<Distance><Unit>/api.xml 

Result:

Example

Error Codes

200OK
404No results found
405Zip codes must be 5 characters in length
406One zip code is invalid
420Rate Limited
421Input is invalid
423API Unavailable
424Source zipcode does not exist


Example XML Error:

Example

Rate Limiting Rules (General)

▶ 5 requests in 5 seconds results in a 15 second block time.
▶ 10 requests in 30 seconds results in a 20 second block time.
▶ 100 requests in 3600 seconds results in a 600 second block time.
100 requests in a single hour is a general limit. We will increase this after the load to the server is known.
▶ 10 requests in 1 seconds results in a 86400 second block time.
10 requests in a single hour is a general limit. We will increase this after the load to the server is known.
▶ 25 requests in 3 seconds results in a 259200 second block time.
25 requests in three seconds results in a three-day block. These limits WILL increase.


Terms of Use

By using the Postcodez.com API, you agree to these simple terms of use. You may use the API as-is for any purpose. You alone are responsible for any damage that you or your users encounter from using services from this API. The data provided may be cached locally for performance, but for no longer than 7 days. We accept no responsibility for any downtime, damage or errors, invalid/incorrect data or the consequences of information we provide. These terms are subject to change without notice and will be updated on this page.