About Intelligent Mail Barcodes
The Intelligent Mail Barcode (IMb), formerly known as OneCode Solution, is a 4-state 1D postal barcode used by the United States Postal Service (USPS) for mail sorting and tracking. Introduced in 2006 to consolidate older postal codes into a single standard, IMb encodes routing and tracking information simultaneously, allowing USPS to track letters and flats from sender to recipient.
How Intelligent Mail Encoding Works
IMb consists of 65 vertical bars representing four states based on their height and position: Tracker (short middle bar), Ascender (extends upward), Descender (extends downward), and Full Bar (extends both directions). It encodes a 20-digit tracking code (containing class, mailer ID, and serial number) and a routing zip code of 0, 5, 9, or 11 digits, totaling up to 31 numeric digits.
Common Applications and Industries
IMb is printed on letters, billing statements, advertisements, and reply mail envelopes sent via USPS. Sorting machines scan the barcode at postal hubs to sort mail, calculate discounts, and provide mailers with real-time tracking updates. It is a mandatory requirement for businesses to qualify for commercial bulk mailing rates in the United States.
Advantages & Limitations
IMb combines routing and tracking data in a single barcode, reducing printing overhead on envelopes. Its 4-state design allows it to be printed in a narrow height that fits within postal headers. The limitation is that it is highly specialized for USPS regulations and cannot be used for retail sales, international shipping, or non-postal tracking.