Intelligent Mail Matrix Barcode (IMmb) Technical Specifications
Shipping labels on irregularly-shaped packages, softpacks, and polybags can easily become distorted or creased during automated parcel processing making reading the traditional, linear IMpb barcode challenging to scan. USPS has developed the IMmb to help overcome these challenges and improve package visibility. IMmb barcodes contain the same data as is in the IMpb barcode; however, they use a more robust, space-efficient robust barcode symbology for encodation. The smaller barcode footprint allows two IMmb barcodes to be added within unused areas of existing standard shipping labels. The result is redundancy of the barcode data giving sorters two additional chances to read the barcode.
The US Postal Service® recommends incorporating the IMmb on all package shipping labels and it will soon become a requirement for HAZMAT shipments.