The Intelligent Mail Barcode is also known as the USPS OneCode Solution or USPS 4-State Customer Barcode (abbreviated 4CB, 4-CB, or USPS4CB). This barcode is adopting a new 4-state 1D barcode that includes more address information than the current code. A sample is shown below.

The Intelligent Mail barcode combines information currently found in the PostNet and Planet barcodes. The length of the barcode is fixed at 65 bars. It also contains a CRC-Checksum for verifying the barcode value. There is no error correction. The output of the barcode is a 20, 25, 29, or 31 digit string (0, 5, 9, or 11 digit zip code) containing the following data:

(© USPS-B-3200,Pages 4-5,file:SPUSPS-B3200B001.pdf)

Statistics

The Mailer ID is a field within the Intelligent Mail barcodes that is used to identify Mail Owners and/or Mailing Agents. The IDs are assigned by the USPS to each Mail Owner and/or Mailing Agent that requests them. A Mailer ID can be a 9-digit field or a 6-digit field. The USPS assigns 6-digit or 9-digit Mailer IDs based upon the mail volume of the mailer.

• The barcode identifier is a 2 digit field assigned by the USPS. The first digit ranges from 0-9 and the second digit ranges from 0-4.
  
  All 6-digit MIDs (Mailer IDs) assigned by USPS will begin with 0 through 8. All 9-digit MIDs will begin with the number 9.

• Special services include a 3 digit field assigned by the USPS for any special services. The range is 000-999.
• The customer identifier is a 6 digit field assigned by the USPS and is unique for each customer. The range is 000000000-999999999.
• The sequence number is a 9 digit field assigned by the mailer for tracking mail pieces. The range is 000000000-999999999.
• The zip code is a 0, 5, 9, or 11 digit zip code. The ranges are none, 00000-99999, 000000000-999999999, 00000000000-99999999999.