USPS Intelligent Mail (USPS 4-State Customer Code)

This module provides a function named func IMb(track, route string) (string, int) for generating USPS Intelligent Mail barcode (IMb), also known as 4-State Customer Barcode. The Intelligent Mail barcode is used by the United States Postal Service (USPS) for sorting and tracking letters and flats, offering enhanced visibility into the mailstream.

Parameters

track: Tracking information for the mailpiece.
route: Routing information for the mailpiece.

Returns

The generated Intelligent Mail barcode string. (len: 64)
Status code. (0 for success)

Structure of Intelligent Mail Barcode (IMb)

The Intelligent Mail barcode consists of the following components:

Barcode ID: A 2-digit field reserved to encode the presort identification.
- Should be "00" if an Optional Endorsement Line (OEL) is not printed on the mailpiece.
Service Type ID (STID): A 3-digit field used to identify the class of mail and additional services.
- Defines the mailpiece as Full-Service, Basic, or Non-Automation.
- Determines the disposition of Undeliverable-As-Addressed (UAA) mail.
Mailer ID (MID): A unique identifier assigned by USPS to Mail Owners or Preparer, Mailing Agents, or service providers based on annual mail volume criteria.
- 9-digit or 6-digit numeric code.
Serial Number: A 6 or 9-digit field defined by the mailer.
Routing Code: A 5, 9, or 11-digit field identifying the delivery ZIP Code data in the address.

Data Type	Data Field	# of Digits
Tracking Code	Barcode Identifier	2 (2nd digit must be 0-4)
	Service Type Identifier	3
	Mailer Identifier	6 or 9
	Serial Number	6 (with 6-digit MID)
		9 (with 9-digit MID)
Routing Code	Delivery Point ZIP Code	0, 5, 9, or 11
Total		31 maximum

Additional Resources

License

MIT License
USPS License Agreement