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Example of a BPO 4 State Code (Royal Mail) barcode BPO 4 State Code, also referred to as ‘British Post Office,’ ‘Royal Mail Code,’ or RM4SCC, is a postal barcode symbology developed by the British Post Office (Royal Mail) for encoding European postcode data in a simple and efficient way. However, it is worth noting that it is not the official European standard for postal applications. The U.S. PostNET symbology encodes numeric characters using four bars. Each bar can be either tall or short, providing 16 possible bar patterns for each set of four bars. This is enough to encode the digits from 0 to 9. European postcodes, however, contain both alpha and numeric characters, requiring a minimum of 36 different patterns. To meet this requirement, the BPO 4 State Code encodes each character into four bars, each with four possible “states”: tall bars, short bars, medium height bars extending up from the middle, and medium height bars extending down from the middle. In theory, the BPO 4 State Code can encode up to 128 different characters, though only characters A to Z and 0 to 9 have been assigned unique bar patterns. BPO 4 State Code is a fixed dimension symbology, meaning that the height, width, and spacing of all bars must fit within exact tolerances. If you need to create BPO 4 State Code, Royal Mail Code, or RM4SCC barcodes, B-Coder Pro can help you generate them easily and accurately. B-Coder Pro is a powerful barcode generation software that supports a wide range of symbologies, including BPO 4 State Code. With B-Coder Pro, you can create high-quality barcodes for your postal applications and streamline your barcode creation process.
Last modified on November 3, 2026