Our Multiple County ZIP Code data helps you with the following problem: ZIP codes cross county lines about 15% of the time (some ZIP codes cross 3 or more counties). For county ZIP Code data, our Multiple County ZIP Code (MCZ) file may be what you need if you need to know all counties which a ZIP Code covers. Some clients use our multiple county zip codes to determine if they can sell or service an area.

We have two unique multiple county ZIP Code products and one of our multiple counties zip code products should work for you.

Note: if you have the full address or ZIP+4 (not just a 5-digit ZIP Code), you can find the exact county by ZIP Code with our Multi-County Max product which will let you know the county by the ZIP+4 code (the 9-digit ZIP Code).

The data includes the ZIP Code, plus the possible counties in which that ZIP Code may cross over. It also has an estimated percentage of the ZIP Code which falls within that county.

For a list of the number of zips which cross county lines per state, click here.

This file is ideal for those applications where you need to know if a ZIP Code is entirely in one county or not, such as:

• Tax calculations
• Insurance rate calculations
• HMO coverage area determination
• Sales territory assignments
• Fraud detection

This file is currently updated about every 2 months. The following fields are included in the data file:

• ZIP Code
• A Sequence Number (for prioritizing the counties within a ZIP Code [sequence 1 is the main county for the ZIP Code])
• State Abbreviation
• City
• County
• State FIPS Code
• County FIPS Code
• Percentage of the total ZIP Code that this county covers

The price for this manually verified product is only $350 per year.

We have spent many hours validating this data. The problem with using address-level data of over 40 million records is that there is a lot of stray records. For instance, in the raw data it shows ZIP Code 30165 in North Georgia crossing Berrien County which is in southern Georgia (over 200 miles away!) It takes a lot of manual work which is what we do with all of our products and distinguishes us from competitors. We are continually working to eliminate the junk!

Go to our Download Page to try a demo of the data!

100% money back guarantee—you can't go wrong!