Data Layout#

Introduction#

The County-ZIP Code Database provides a comprehensive list of ZIP codes and their corresponding counties across the United States and its territories, as served by the USPS. Unlike other databases that link a single county to each ZIP code, this unique database accounts for ZIP codes that span multiple counties due to real-world boundary overlaps. For instance, over 20 percent of ZIP codes fall within more than one county. This database is valuable for identifying ZIP codes within or overlapping specific counties, as well as finding counties containing parts of a particular ZIP code. It also includes preferred city names for ZIP codes and county FIPS codes. Available in comma-delimited ASCII format, the database is easily importable into various database programs, searchable by text editors, and adaptable to different computer systems. Compiled by Melissa from diverse sources, including USPS, the database strives for accuracy across its approximately 55,000 records.

List of Files#

Fixed length (ASCII)
FoxPro (DBF)
ACCDB
XLSX
CSV

Layout and Definitions#

County-ZIP Code Database (cz.txt)#

Column Name

Type

Definition

County

varchar(25)

The County Name field identifies a county which contains some or all of the ZIP code identified by the ZIP code field.

ZIP

char(5)

The ZIP Code field identifies one ZIP code which lies at least partially within the boundaries of the County identified by the County Name field.

Type

char(1)

The ZIP Code type field identifies special kinds of zip codes. For normal residential ZIP codes, this field is blank.

FIPS

char(5)

The County FIPS Code is a 5-digit field containing a unique numeric identification assigned to each county in a given state by the US government.

City

varchar(28)

The City Name field identifies the one (preferred) city associated with the particular ZIP code and not necessarily the County by the USPS.

ST

char (2)

The State Code is the USPS 2 character state abbreviation, such as CA for California.

Addr Cnt

char(5)

The address record count field identifies the number of ZIP+4 address records which list both that one particular County and that one particular 5-digit ZIP code. This field provides a method of determining the relative portion of a given ZIP code which lies within a given county. Note, however, that this number is not based on area or population, but an actual ZIP+4 address records in the USPS ZIP+4 address database (not included with this database). Note that in the case of an inactive ZIP code (assigned but unused) this count is zero, indicating that this particular ZIP code is actually not in use at this time).

Prev?

char(1)

The prevalent-County Flag is set to “Y” if the county shown in this record contains the largest portion of this ZIP Code. For each ZIP code there should be only one record containing a “Y” in this field. If the ZIP code lies in more than one County, there will be multiple records containing this ZIP code, but only one of these records will have the Prevalent-County flag set to “Y”.

Mult

char(1)

The Multiple-County Flag is set to :”Y” if the ZIP code of this record lies within the boundaries of two or more counties. This field is set to “Y” for all records for a ZIP code that lies in more than one county. If this flag is set to blank, then the ZIP code lies in only one county and has only a single record in this database. In other words, this record is the only record iwhich contains this particular zip code. It also measn that this Zip code lies completley within the boundaries of the county specified in this record.

State FIPS Code Database (stfips.txt)#

Column Name

Type

Definition

ST FIPS

char(5)

The Federal Information Processing Standard (FIPS) is a 5-digit number assigned to each county in the U.S. by the Census Bureau. The first two digits are the state code and the last three digits are the county number

ST

char(2)

The 2-character USPS State Abbreviation (“CA”, etc.)

Name

char(40)

State Name or Equivalent Name

Code and Definitions#

County-ZIP Code Database (cz.txt)#

Column Name

Code

Definition

Type

P

ZIP Code applies only to PO Boxes

M

Military ZIP code (APO/FPO)

U

Unique ZIP Code assigned to one business or organization

Blank

Normal Residential ZIP Codes