CASS Intelligent Mail Barcode (IMb) Standards & Application 2 — Questions and Answers
Question 1: In the IMb structure, what does the Barcode ID (BID) field consist of?
- 1 digit identifying mail type only
- 2 digits identifying the presort level and barcode usage (Correct answer)
- 3 digits identifying the mailing campaign
- 4 digits identifying the postage payment method
Correct answer: 2 digits identifying the presort level and barcode usage
The Barcode ID is a 2-digit field within the IMb that identifies the presort level of the mailpiece and indicates whether the barcode is used for basic or Full-Service processing.
Question 2: How many different bar states does each bar in an Intelligent Mail barcode have?
- 2 states (up or down)
- 3 states (tracker, ascender, descender)
- 4 states (tracker, ascender, descender, full) (Correct answer)
- 5 states including a neutral position
Correct answer: 4 states (tracker, ascender, descender, full)
Each of the 65 bars in an IMb has 4 possible states — tracker (short middle bar), ascender (extends upward), descender (extends downward), and full (extends both up and down) — allowing the barcode to encode more data per bar.
Question 3: When did USPS mandate the use of Intelligent Mail barcodes as a requirement for automation price eligibility?
- January 2009
- January 2011
- January 2013 (Correct answer)
- January 2015
Correct answer: January 2013
USPS made the IMb mandatory for all mailings claiming automation prices effective January 28, 2013, requiring mailers to transition from legacy POSTNET barcodes.
Question 4: What is the primary purpose of the IMb Tracing service offered by USPS?
- To verify address deliverability before a mailing is submitted
- To track individual mailpieces as they move through the postal processing and delivery network (Correct answer)
- To generate postage statements and manifests automatically
- To validate Mailer ID assignments issued by USPS
Correct answer: To track individual mailpieces as they move through the postal processing and delivery network
IMb Tracing is a USPS service that uses scan data captured at postal processing facilities to provide mailers with visibility into when and where their individual mailpieces were scanned during delivery.
Question 5: In a Full-Service IMb mailing, how must the Serial Number be assigned to comply with USPS requirements?
- Sequentially starting at 000000001 and resetting for every new mailing
- Randomly generated without any reuse restriction
- Uniquely per combination of Mailer ID and STID, with no reuse within a 45-day period (Correct answer)
- Based solely on the destination ZIP Code of each mailpiece
Correct answer: Uniquely per combination of Mailer ID and STID, with no reuse within a 45-day period
Full-Service IMb rules require that each barcode serial number be unique for a given Mailer ID and STID combination, and that serial numbers not be reused within a 45-day window to ensure piece-level uniqueness for tracking.
Question 6: Which component of the Intelligent Mail barcode identifies the specific mailpiece within a mailer's production run?
- Service Type Identifier (STID)
- Barcode ID (BID)
- Serial Number / Sequence Number (Correct answer)
- Routing Code
Correct answer: Serial Number / Sequence Number
The Serial Number (sometimes called the Sequence Number) is the field within the IMb that the mailer assigns to uniquely identify each individual piece within a campaign, enabling piece-level tracking.
Question 7: What is the relationship between Mailer ID length and Serial Number length in the Intelligent Mail barcode?
- Both are always 6 digits regardless of configuration
- A 6-digit MID pairs with a 9-digit serial number; a 9-digit MID pairs with a 6-digit serial number (Correct answer)
- A 6-digit MID pairs with a 6-digit serial number; a 9-digit MID pairs with a 9-digit serial number
- The serial number length is always fixed at 8 digits regardless of MID length
Correct answer: A 6-digit MID pairs with a 9-digit serial number; a 9-digit MID pairs with a 6-digit serial number
The MID and Serial Number lengths are complementary: a 6-digit MID is paired with a 9-digit serial number, and a 9-digit MID is paired with a 6-digit serial number, so both combinations always total 15 digits in the IMb.
CASS Intelligent Mail Barcode (IMb) Standards & Application 2
In the IMb structure, what does the Barcode ID (BID) field consist of?