POSTNET Barcode Introduction

POSTNET (Postal Numeric Encoding Technique) was invented by US Postal Office to sort mail. It is often printed on envelopes and business return mail.
POSTNET was retired, and has been replaced by the Intelligent Mail barcode, which combines all previous Postal Service barcodes and marking into a single barcode.

Encodable Chars	POSTNET encodes digit 0,1,2,3,4,5,6,7,8,9 It encodes 5, 6, 9, 11 digits only without the last check digit
Checksum Digit	POSTNET bar codes always include a modulo 10 check digit.
Technical specification	POSTNET actually encodes data in the height of the bars. That is why all the bars are essentially the same width but vary only in height.

 

Quiet Zone	Frame Bar	Data Digits	Check Digit	Frame Bar	Quiet Zone
1	2	3	4	5	6