Postal and Shipping Symbologies

Symbologies that are used for letters, postcards, bulk mail, and other "flats" by postal systems worldwide are, with a few exceptions, based on the Royal Mail 4-State Customer Barcode that was developed in the United Kingdom. In a 4-state symbology, all bars and spaces have the same width, but the bars vary by height. All postal symbologies enable the automation of mail sorting and classification.

Packages that are sent by mail are typically marked with symbols that are associated with the transportation and logistics industry, such as GS1-128.

The shipping industry typically uses general-purpose symbologies (such as Code 128) or the GS1 implementations (such as ITF-14) for packages that are transported outside of postal systems. An exception is MaxiCode, which was developed by United Parcel Service (UPS) and is described in this section.