About Royal Mail Barcodes
The Royal Mail barcode, officially known as RM4SCC (Royal Mail 4-State Customer Code), is a 4-state postal barcode used in the United Kingdom to automate mail sorting. Developed by Royal Mail, it encodes postal codes, street numbers, and delivery point details, allowing sorting machines at UK postal hubs to organize letters down to individual delivery walks.
How Royal Mail Encoding Works
RM4SCC consists of vertical bars of varying heights that represent four distinct states: Tracker (short middle), Ascender (extends up), Descender (extends down), and Full Bar. Each character is encoded by four bars containing two ascenders and two descenders. The barcode starts with a start bar, ends with a stop bar, and includes a checksum character calculated using a modulo-6 table.
Common Applications and Industries
RM4SCC barcodes are printed on letters, magazine mailings, utility bills, and bank statements in the UK. British businesses print them on envelopes to receive postal discounts. RM4SCC is also the base standard for KIX (Dutch postal) and Singapore Post barcoding, making it a highly influential postal standard across Europe and Asia.
Advantages & Limitations
RM4SCC offers high data density for alphanumeric UK postcodes in a compact vertical profile. Its 4-state structure makes it highly tolerant of printing variations on envelopes. The limitation is that it is strictly optimized for UK postal systems and European variations, with no application in retail inventory or international shipping logistics.