Postnet Introduction
This page concerns basic information of Postnet, as well as its generating and printing components.
How to generate, print barcode using .NET, Java sdk library control with example project source code free download:
Postnet Overview

This part talks about the
Postnet barcode. Postnet, Postal Numeric Encoding Technique, is a barcode symbology that was used by the United States Postal Service for mail sorting and routing. Data is encoded in half- and full-height bars, similar to Planet, another USPS postal code. This is quite different from other barcodes which encodes data in the width of the bars.
Generating and Printing Postnet Barcodes
OnBarcode provides comprehensive Postnet generators and scanner components for Java, .NET, Android, iOS developments and several reporting applications.
Postnet Structure
Postnet Barcode Size Setting
As for Postnet size setting, three factors should be considered: bar width (i.e. X dimension) barcode width.
Postnet Data Encoding
Being a postal barcode symbology, Postnet encodes only numeric digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.
Postnet Barcode Checksum Digit
Postnet specifications require a module 10 checksum digit, which will be automatically added by OnBarcode Postnet barcode generator software & components.
Postnet Barcode vs Planet Barcode
Similarities:
- Postnet barcode and Planet barcode are similar in that both encode data in half- and full-height bars.
- Both use a Code 2 of 5 encoding scheme.
- Both barcodes start and end with a full bar, called a guard rail.
- For both barcodes, each individual symbol digit is represented by a set of 5 bars.
Difference:
- Planet can encode 11 or 13 digits (excluding the last checksum digit ), while Postnet can encode 5, 6, 9 or 11 digits ( checksum digit excluded).
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