USPS Intelligent Mail IMb Tutorial

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USPS Intelligent Mail IMb Overview

Create Intelligent Mail Barcodes using Postnet Barcode Fonts

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The Intelligent Mail barcode (IMb) is the term coined by the United Stated Postal Service (USPS) for the new barcode symbology used to track and sort letters and flat packages. It comprises a suite of services including the Confirm® Service, which is referred to as OneCode Confirm™, and the Address Change Service™, which is referred to as OneCode ACS™. Intelligent Mail is also a term used in the description of the 24 digit tray label barcode.

The Intelligent Mail customer barcode combines the information of both the POSTNET and PLANET symbologies, and additional information, into a single barcode that is about the same size as the traditional POSTNET symbol. Automation Discounts with the use of Intelligent Mail customer barcodes have been supported since March 2007. Version 7.0 of the Postnet & Intelligent Mail Barcode Fonts contains the special characters required.

Currently, the use of the Intelligent Mail barcode is optional. Since it offers significant advantages, however, it makes good business sense to implement this new symbol today. IDAutomation has implemented unique encoding in IDAutomation’s Postnet Fonts, which allow printing of Postnet, Planet and Intelligent Mail barcodes with the same font.

Formatting USPS IMb


To create a proper Intelligent Mail Tracing, OneCode Confirm or OneCode ACS Barcode with IDAutomation’s products, a single string of numbers must be obtained, which is referred to as the DataToEncode. The DataToEncode is usually* made up of the following:

 TypeFieldDigitsExample
 Tracking CodeBarcode Identifier2 (2nd digit must be 0-4)01
 Special Services3234
 Customer Identifier6 or 9567094
 Sequence Number9 or 6 if 9 were used above987654321
 Routing CodeDelivery Point ZIP Code0, 5, 9, or 1101234567891
 Complete string from data above: 0123456709498765432101234567891
  • The Barcode Identifier field is a 2-digit field reserved for future use to encode the presort identification that is currently printed in human-readable form on the optional endorsement line (OEL). Initially, OneCodeCONFIRM and OneCodeACS users should leave this field as “00”. Later, the USPS may require the proper coding of this field.
  • The Special Services field is a 3-digit field that identifies the type of service. In the end, the field is intended to allow a single 4CB to support multiple services in addition to or instead of Confirm and ACS.
  • The Customer Identifier field is a 6-digit number identifying the mailer. At the initial launching of 4CB, Destination Confirm appends a leading zero to the assigned 5-digit Subscriber ID to form the Customer Identifier field.
  • The Sequence Number is a 9-digit field. For Destination Confirm, this field holds the existing Mailing ID field, which is a 4- or 6-digit field. The Mailing ID field can be expanded to 9 digits if so desired. Otherwise, leading zeros should be used to fill the field completely. When using Origin Confirm, the Customer Identifier field and the Sequence Number field may be combined into a 15-digit field to hold the existing 9- or 11- digit Customer field plus additional digits. If these fields are not expanded to 15 digits, leading zeros should be used to fill the field completely.
  • The Routing ZIP Code field will accommodate 0, 5, 9 or 11 digit ZIP Code information. Confirm requires a 9- or 11-digit Routing ZIP to serve as “Subscriber ID” for Origin Confirm users. The routing ZIP Code inserted into the 4CB must be registered in the Confirm account.

* Always refer to the most recent specification from the USPS before production.

Printing and Generating USPS IMb

USPS Intelligent Mail & OneCode Barcode ExampleAfter the DataToEncode is obtained, the Intelligent Mail Barcode may be easily generated and printed with the IDAutomation Postnet & Intelligent Mail Barcode FontsBarcode Components or Barcode Applications. Intelligent Mail is currently supported in the latest version of the products in the selection dialog below.

Barcode Generation Examples:

When using IDAutomation Intelligent Mail Barcode Fonts, a font encoder must be used to generate the text string for the Intelligent Mail barcode font because of the complex encoding algorithms used in this symbology. This generated string will create a correct barcode when combined with the IDAutomation Postnet Font. The text below was generated from the example data string of 0123456709498765432101234567891:
qqrspprpsrqrsqqrqqsprsrrqqqrrsrssrqpqrqrrrsppprrsssqrpqqqrpsrqqrq

Intelligent Mail Barcode images may be created dynamically from the Dynamic Barcode Generator Service, for example:

https://www.bcgen.com/demo/linear-dbgs.aspx?CODE_TYPE=18&BARCODE=0123456709498765432101234567891&X=.06&FORMAT=GIF

(Generating images from BCGEN is subject to the Free License portion of the License Agreement. The licensed version does not contain the watermark.)

Symbol Size:

The size of the Intelligent Mail barcode must be between 22 and 24 bars per inch. Additional font widths are provided with IDAutomation’s Postnet Fonts for fine-tuning and adjustment. IDAutomation recommends verifying the printed symbols of random selections of mail to ensure proper dimensions. When using Barcode Components or Barcode Applications, the height and width may be adjusted as necessary as long as the properties are within USPS Specification Tolerances, which are shown in Fig. 1 below.

Fig. 1: USPS Specification Tolerances for the USPS Intelligent Mail IMb Barcode:

PropertyIDAutomation Font DimensionsUSPS Specification Tolerances
X Dimension (bar width)0.017″ [0.043 CM]0.015″ – 0.025″ [0.038 – 0.063 CM]
Space between bars0.026″ [0.066 CM]0.012″ – 0.040″ [0.030 – 0.101 CM]
Size of tall bar0.135″ [0.342 CM]0.125″ – 0.165″ [0.317 – 0.419 CM]
Size of tracker (short) bar0.041″ [0.104 CM]0.039″ – 0.057″ [0.100 – 0.144 CM]
Number of bars per inch2322 – 24
Location of the Symbol:

Intelligent Mail and OneCode barcodes must be printed on specific areas of mail, usually directly above the name and address. Additional details pertaining to the placement of the symbol are available in the addenda to Publication 8, Address Change Service, and Publication 197, Confirm® Service User Guide, which may be obtained from the USPS website.

Verifying IMb

Printed symbols may be easily verified with the Print Quality Assessment (PQA) tool found in the IDAutomation 2D Barcode Scanner. The quality assurance test grades the symbol and reports any possible problems and dimension errors. The report below was generated when scanning the barcode symbol at the top of this document with PQA enabled:

10,301,107081,000000000,33609106255 >> PQA <<
INTELLIGENT MAIL BARCODE(USPS): 65 Bars, nominally from 02.66 to 03.20 in. in Width
Bar Sequence: THHHTDDHAADAHAAHDHDATHDAAATDTTTTAADHTAADTAATHATATTTTDDDAAHDATATAH
[C] (Lo) < "Tall" Bar Extensions: 0.062 in. from center
[B] (Lo) < "Short" Bar Extensions: 0.021 in. from center
[B] (Lo) < Bar Widths = 0.015 in.
[A] (Ok) < Inter-Bar Gaps = 0.030 in.