The Intelligent Mail barcode or IMB (formerly known as the 4-State Customer Barcode or 4CB or USPS4CB) is a new type of bar code introduced by USPS in USA. Although similar barcodes have been in use in other countries for quite a while, IMB gets accepted in USA recently. It can encode tracking code and routing number in 65 bars, hence combines the capabilities of the POSTNET™ barcode and the PLANET Code® barcode into one unique barcode. Unlike POSTNET and PLANET, where two variations of bars (long and short) have been used, IMB uses 4 variations of bars: tracker, ascending, descending, full. We will discuss these in details in barcode structure section.

Compose Intelligent Mail Barcode Data

As we already know that Intelligent Mail Barcode can encode tracking number which is 20 digits long and a routing number or delivery point zip code which can be 0 to 11 digits long. Therefore Intelligent Mail Barcode or IMB can encode up to 31 numeric values. Although alpha numeric value can be encoded with 4 state code, IMB only encodes numeric value for now.

  1. Tracking Code: Tracking code composed of the following sections:
Barcode Identifier 2 (2nd digit must be 0–4)

E.g., Value Optional Endorsement Line (OEL) Description

00 Default / No OEL Information

10 Carrier Route (CR), Enhanced Carrier Route (ECR), and FIRM

20 5-Digit/Scheme

30 3-Digit/Scheme

Etc.

 It is assigned by USPS to encode the presort identification which is currently stated as human readable on the optional endorsement line (OEL).
Service Type Identifier 3 3 digits long

700 = First-Class Mail with no services

702 = Standard Mail with no services

704 = Periodicals with no services

706 = Bound Printed Matter with no services

 It is also assigned by USPS for any combination of services requested on the mail piece.
Mailer Identifier 6 or 9 digits depending on serial number stated below.

Mailer ID & serial number combined should be 15 digits long

 The Mailer Identifier is a 6 or 9 digit number assigned by USPS to identify a business entity who is sending the mail piece..
Serial Number 6 (when used with 9 digit Mailer ID)

9 (when used with 6 digit Mailer ID)

 The Serial Number is a 6 or 9 digit number set by the mailer to uniquely track and identify the mail piece.
  1. The routing Number: The routing number or The Delivery Point ZIP Code is set by the mailer for routing the mail piece. Mailer can leave this blank or set to 5, 9, or 11 digits long.