A Closer Look at the POSTNET Barcode

POSTNET is the barcode used by the United States Postal Service (USPS) to direct mail to the correct recipient.  You’ve probably seen this barcode on the bottom of your mail almost as often as you see UPC’s.  POSTNET is a numeric only symbol that is capable of encoding digits 0-9 with each character represented by five bars (two tall and three short).  The POSTNET symbology can be printed as a 5-digit POSTNET barcode, a 9-digit ZIP+4 POSTNET barcode, or an 11-digit DPBC POSTNET barcode.  Let’s take a look at each of these options and what they encode:

5-Digit POSTNET Barcode- Pictured below, the traditional POSTNET barcode contains a total of 32 bars and consists of a start character, the 5-digit ZIP Code, check digit and the stop character.



9-Digit ZIP+4 POSTNET Barcode– The 52 bar symbol pictured below is an example of a ZIP+4 POSTNET barcode.  The additional four digits provide a more precise location than the ZIP code alone.  This symbol consists of a start character, the 9-digit ZIP code data, check digit and stop character.



11-Digit DPBC (Delivery Point Barcode) POSTNET– This 62 bar option pictured below encodes an additional two digits called a DPBC (Delivery Point Barcode); these two numbers are normally the last two digits of a street address, PO Box, or route number.  This symbol consists of a start character, 9-digit ZIP code, 2-digit DPBC, check digit and stop character.


When using this symbology, you need to be sure that it meets specifications and can be scanned by the USPS equipment or you’re setting yourself up for a major headache.  For more information about POSTNET requirements, you can read the POSTNET Barcode Certification Guide.  To easily begin using POSTNET, you can purchase professional labeling software such as NiceLabel.  You can be assured that this software supports all POSTNET symbols and meets all standards.  If you’d like more information about NiceLabel or other labeling software, please contact me at ehodges@barcode.com.