# Intelligent Mail barcode

A possible Intelligent Mail Barcode for the Wikimedia Foundation address

The Intelligent Mail Barcode (IM barcode) is a 65-bar code for use on mail in the United States. The term “Intelligent Mail” refers to services offered by the United States Postal Service for domestic mail delivery. IM Barcode is intended to provide greater information and functionality than its predecessors POSTNET and PLANET. Intelligent Mail barcode has also been referred to as One Code Solution and 4-State Customer Barcode abbreviated 4CB, 4-CB or USPS4CB. The complete specification can be found in USPS Document USPS-B-3200E.[1] It effectively incorporates the routing ZIP code and tracking information included in previously used postal barcode standards.

The Postal Service will require use of the Intelligent Mail barcode to qualify for automation prices beginning January 28. 2013.[2] Some of the benefits include improved deliverability, new services and increased overall efficiency.

## Symbology

The four types of symbols in an Intelligent Mail barcode.

The Intelligent Mail barcode is a height-modulated barcode that encodes up to 31 decimal digits of mail-piece data into 65 vertical bars.[1]

The code is made up of four distinct symbols, which is why this barcode was once referred to as the 4-State Customer Barcode. Each bar contains the central "tracker" portion, and may contain an ascender, descender, neither, or both (a "full bar").

The 65 bars represent 130 bits (or 39.13 decimal digits). Those 130 bits are grouped as ten 13-bit characters. Each character will have 2, 5, 8, or 11 of its 13 bits set to one. The Hamming distance between characters is at least 2. Consequently, single-bit errors in a character can be detected (adding or deleting a one bit results in an invalid character). The characters are interleaved throughout the symbol.

The number of characters can be calculated from the binomial coefficient.

$\binom{13}{2} + \binom{13}{5} + \binom{13}{8} + \binom{13}{11} = 78 + 1287 + 1287 + 78 = 2 \cdot 1365 = 2730$

Total number of character are 2 times 1365 for 2730. Log2(2730) is 11.41469. So the 65 bars (or 130 bits) encode a 114-bit message.

The encoding includes an eleven-bit cyclic redundancy check (CRC). Subtracting the 11 CRC bits from the 114-bit message leaves an information payload of 103 bits (the specification sets one of those bits to zero). Consequently, 27 out of the 130 bits are devoted to error detection.

The encoding scheme does not use error correction.

The IM barcode carries a data payload of 31 digits representing the following elements:

 Index of first digit Length Name 1 2 Barcode identifier 3 3 Service type identifier 6 6 or 9 Mailer ID 12 or 15 9 or 6 Sequence number 21 11 Delivery point ZIP code

### Barcode identifier

The Barcode Identifier shall be assigned by USPS to encode the presort identification that is currently printed in human readable form on the optional endorsement line (OEL) as well as for future USPS use. This shall be two digits, with the second digit in the range of 0–4. The allowable encoding ranges shall be 00–04, 10–14, 20–24, 30–34, 40–44, 50–54, 60–64, 70–74, 80–84, and 90–94.

The list of valid field values is as follows:

Value 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

### Service type identifier (STID)

A three-digit value representing both the class of the mail (such as first-class, standard mail, or periodical), and any services requested by the sender.

Basic STIDs for the purpose of automation only, are as follows:

Value STID Description
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
710 Priority Mail with no services
712 Priority Mail Flat Rate with no services

For a detailed list of STIDs, see Appendix A of the USPS Guide to Intelligent Mail Letters and Flats[3] or Service Type Identifiers.[4]

### Mailer ID

A six or nine-digit number assigned by the USPS that identifies the specific business sending the mailing. Higher volume mailers are eligible to receive six-digit Mailer IDs, which have a larger range of sequence numbers associated with them; lower volume mailers will receive nine-digit Mailer IDs. To make it possible to distinguish six-digit IDs from nine-digit IDs, all six-digit IDs begin with a digit between 0 and 8, inclusive, while all nine-digit IDs begin with the digit 9.

### Sequence number

A mailer-assigned six or nine-digit ID specific to this piece of mail, in other words, to identify the specific recipient or household, which the mailer must ensure is unique for a 45-day period after it is sent if you are claiming the Full Service discount; if not, it doesn't have to be unique. The Sequence Number is either six or nine digits, based on the length of the Mailer ID. If the Mailer ID is six digits long, then the Sequence Number is nine digits long, and vice versa, so that there will always be fifteen digits in total when the Mailer ID and the Sequence Number are combined.

### Delivery point ZIP code

This section may be omitted, but if it is present, the five, nine, or eleven-digit forms of the ZIP code are also encoded in the Intelligent Mail barcode. The full eleven-digit form includes the standard five-digit ZIP code, the ZIP + 4 code, and a two-digit code indicating the exact delivery point. This is the same information that was encoded in the POSTNET barcode, which the Intelligent Mail barcode is intended to replace.

## Implementation

Barcodes can be printed on documents (shown through a window envelope) or directly onto envelopes at various points in the process. Many large companies may use some or all of these approaches based on their business needs and environment, as well as the unique characteristics of an application.[5]

### Document composition

In recent years, more companies have been applying barcodes as part of document creation, with all barcode information included in the initial data payload. This trend has been driven by other initiatives, such as transpromotional transaction documents, where the goal is individualized, relevant statements. Creating barcodes at this point in the process may require some added effort, but with the proximity to databases and business applications, some may find it easier to track back data (such as a corrected address) to its original data source.

### Document production

With today’s document output technologies, mailers can modify and reengineer print streams – moving and adding information (such as barcodes) on the fly. Likewise, mailers can print barcodes directly on envelopes using an envelope finishing system. Either way, this approach enables mailers to centralize and standardize barcode creation on the production floor using the original data files—without impacting the upstream business applications.

### Post-composition document re-engineering

Many organizations may not be able to place IMBs during the document composition step. There may not be sufficient resources to make the production modifications, or the transaction print data stream may come in already composed without the ability to reach back and change the composition process. But the organization may still want to place the IMB into the electronic document before it is printed rather than later in a post-print production process.

Adding Intelligent Mail barcodes post-composition into the electronic print file allows organizations to simultaneously clean up all their transaction print streams while adding the IMBs they need. Other document re-engineering options can also be made at this step, such as adding 2D barcodes for use by the newer Automated Document factory (ADF) systems, checking address blocks, and adding more marketing messages.

### Electronic commingling

Many organizations are finding that by commingling multiple smaller print streams before printing into one larger stream (or a few larger streams, sorted by criteria such as weight or number of inserts) they can gain efficiencies and reduce overall postage costs. During this electronic commingling process IMBs can be added to the documents and mail pieces in the new stream(s). This is an option to in-house sortation.

### In-house sorting

When mailers run separate jobs and then want to combine them to achieve additional postal savings, they can physically sort mail after it’s produced using sorter equipment. With new or upgraded sorter technology, mailers can accommodate the new Intelligent Mail barcode at the end of the mail production process. This is an option to electronic commingling.

### Third-party presorting

Third-party presort houses may provide mailers an easy way to comply with Intelligent Mail mandate and also provide the benefits of commingled mail. Even if a third-party applies the barcode, however, it may still be possible for the USPS to monitor the quality of the sortation using a mailer’s unique Mailer ID. It will also be important for mailers to coordinate sequence numbers with their vendor so they can leverage OneCode ACS and OneCode Confirm services.

## References

1. ^ a b "Intelligent Mail Barcode Specification" (PDF). United States Postal Service. March 11, 2009. pp. page 3. Retrieved 2011-07-20.
2. ^ "Intelligent Mail Services Latest News" (PDF). United States Postal Service. September 21, 2012. Retrieved 2012-9-27. "The Intelligent Mail barcode, formerly referred to as the 4-State Customer barcode, is a new Postal Service barcode used to sort and track letters and flats. The Postal Service is promoting use of the Intelligent Mail barcode because it expands the ability to track individual mailpieces and provides customers with greater visibility into the mailstream."
3. ^ USPS Guide to Intelligent Mail Letters and Flats
4. ^ Service Type Identifiers, February 7, 2011, retrieved 2011-12-01
5. ^ "Implementing the Intelligent Mail Barcode" (PDF). Pitney Bowes. 2008-09-23. Retrieved 2010-12-19. "Based on the final USPS Federal Register Notice, mailers looking to take advantage of the lowest automation prices will need to replace the current POSTNET barcode with the new Full-Service Intelligent Mail barcode in the fall of 2009. .... The USPS will provide mailers with two options: Full-Service and Basic. The Basic option will have fewer requirements. The Full-Service option will provide access to more services (such as free ACSTM and Start the Clock information*) and will enable mailers to earn the greatest postal discounts as of the fall of 2009."