All payment meters have associated with them a Decoder Reference Number (DRN), made up in part of a manufacturer code, to be able to distinguish the manufacturer of the payment meter. The encryption and decryption algorithms make use of this unique DRN in order to render tokens unique to a specific payment meter.

Each manufacturer, who is a member of the STSA, is issued with a unique 2- or 4-digit manufacturer code to be used in the manufacture of STS compliant payment meters.

The manufacturer codes issued to new members are initially issued as provisional codes for a period of two years. If the manufacturer does not successfully complete STS compliance for his product within this provisional period, the manufacturer code issued to him may be recalled by the STSA and made available for issue to another member.

Code Of Practice STS403-1 contains the rules for the generation and use of manufacturer codes.

Manufacturer codes are not issued to Vending system manufacturers.

The following manufacturer codes are specified: