Intelligent Mail Barcode (IMb) Resources

The Intelligent Mail Barcode (IMb) is the USPS standard barcode for letter and flat mail. IMb replaced the older POSTNET and PLANET barcodes and is now required for Full-Service mail processing and automation postage discounts. Mail Movers helps businesses understand and implement IMb compliance for their outgoing mail.

What Is the Intelligent Mail Barcode?

IMb is a 65-bar barcode that encodes routing information, tracking data, and mailer identification. It appears on the address side of every piece of automation-compatible mail and enables USPS to sort, route, and track individual mail pieces through the postal network.

Why IMb Matters

• Required for automation discounts: USPS automation postage rates require IMb on every piece.
• Required for Full-Service: Full-Service certification requires unique IMb on every piece, tray, and container.
• Enables mail tracking: IMb provides scan-based tracking of individual pieces through the USPS network.
• Enables Informed Delivery: IMb is required for USPS Informed Delivery interactive campaigns.

IMb Components

• Barcode Identifier: Identifies the mail class and service type
• Service Type Identifier: Specifies handling services (forwarding, return, etc.)
• Mailer ID: Identifies the mailer (assigned by USPS)
• Serial Number: Unique identifier for each mail piece
• Routing Code: ZIP code or delivery point for sorting

How Mail Movers Handles IMb

As a USPS Full-Service Certified provider, Mail Movers applies unique Intelligent Mail Barcodes to every piece we process. We handle all IMb generation, application, and electronic documentation — you don't need to understand the technical details.

What Is IMb? (Detailed Guide) | Full-Service Certified | Informed Delivery | All Equipment