Determining the County Name for a Zip Code or Address

A common business problem is to find the county where a customer resides.   This can be required to determine sales tax or to obtain other background information on a location.   County can be determined by either the zip code or the full address.   The method of determining county by address is more accurate since a zip code can contain more than one county.

CDX Technologies offers a variety of tools which allow you to determine county and many other data items for a zip code or address.   Which product you choose depends on the data you need, the technology platform in use and on the number of reports/requests you expect to do.

If you have just a few addresses, you can use our free online tools to do this.  For instance, to determine the county you can use our Zip Code Lookup Tool to generate a report for a zip code which includes the county name and many more data items.  Simply enter the zip code you wish to view and then press “Generate Report”.  The county shown is the primary county for this zip code. A typical report will look like:

More detailed information on this tool can be found in our blog article “Free Zip Code Lookup for City, County, State and More”.

If you have a full address our online tool for Address Correction and Zip+4 data can be used.  This tool links to a USPS database to determine valid addresses, correct spelling errors and return Zip+4 and other associated data for an address.  Address data can be entered as a single string or in a multi-line format.   A typical report is shown in the following image.

This report provides the specific county name for any US address.  For a tutorial on using this tool please see the video “Free Address Correction and Zip+4 Lookup”

If you have many addresses to process our “Bulk Address Correction and Zip+4” online tool is the fastest way to do this.  Your data is uploaded in an Excel or CSV file.  Both single column and multi column formats are supported.   The tool will automatically search for the required columns and then present a preview of the output report.

If our software can't identify the input format a screen will be presented allowing you to match columns to the expected address fields.   All of the data items in the free report (such as county) are included in the csv report output. 

For one-time reports pay $.01 per address using your credit card or PayPal (minimum charge of $9.95). Up to 20,000 address can be processed in a single report. For a quick review of how to use this tool check out this Youtube video.  You can also use a pre-purchased CDXStreamer account for lower costs and no minimum charge.

If you just have a list of zip codes and need to determine the primary county for each use our “Zip Code Demographic Batch Report”.   Create a csv or Excel file with zip codes in a single column and upload it to the tool.   The output file contains county name as well as many other demographics covering population and income statistics for the zip code.  You can use your CDXStreamer account or pay .01 per zip code for one-time reports.

Each of our 3 major products have the capability determine county name and many other data items by zip codes of address.  

  1. CDXZipStream - CDXZipStream is a Windows based Excel add-in that can produce bulk zip code or address reports. 
  2. CDXStreamer - If you prefer to work in the browser as described in the online tools above, choose this subscription service.
  3. CDXGeodata - If you are developing your own solution and need a web service API for zip code lookup and address correction consider our CDXGeodata This solution is platform independent and will work on both the Mac and Windows.

Each of these 3 products offers the ability to create a custom formulas in Excel to return county name by zip code or address thru the use of add-in techology.   Formulas are then copied down you list to quickly create reports.  Here is an video tutorial of doing this with CDXZipStream. Pre-configured templates are also available to automate this operation.

The features described above are just a small sampling of the capabilities that CDX Technology products offer.  Not only county name but hundreds of different data items can be retrieved.   Each of these products also includes advanced location analytics such as distance, geocoding and radius reports.   Free demos are available so you can try before you buy.  For more information please visit









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