Barcode-Glossary

POSTNET

Origin and Symbology Term

POSTNET (POSTal Numeric Encoding Technique) was developed by the United States Postal Service (USPS) in 1982 in order to encode the ZIP Code and the address information on letters in such a way that they could be read quickly and reliably by sorting devices. The code is also called the 2 -State Code, due to the two bar heights (full and semi height)

Examples of the different POSTNET Symbols:

Postnet 11 DPC:

POSTNET 11 DPC

Postnet 5 ZIP + 4:

POSTNET 5 ZIP + 4

Postnet 9 ZIP + 4:

POSTNET 9 ZIP + 4

Ranges of Application & Businesses/Trades

  • Post

Classification

  • 2 State Barcode
  • One-Width Barcode

Codeable Character Set

  • 0 1 2 3 4 5 6 7 8 9

Symbol Setup

Each POSTNET character represents a figure comprising of five bars (bits). The spaces carry no information. Combinations of two tall and three semi-tall bars encode the ten figures. All other combinations will be identified as errors. The height of the bars is firmly pre-defined. The separation of the bars can be modified to a small extent.

Check Digits & Data Security

Due to the pre-defined setup of each single figure, consisting of two tall and three semi-tall bars, a type of security level is already built-in. The POSTNET-Code contains a check digit, calculated according to Modulo 10. The check-digit is automatically generated by the „Visual Bar Code Designer“.

Symbol Description

Starting from the left, a symbol consists of:

  • A leading quiet zone,
  • A Frame Bar,
  • The figures carrying information,
  • A check digit,
  • A Frame Bar,
  • A closing quiet zone