ISO/IEC 7816-5 defines how the application identifier is to be used to determine the presence of an application on a card and/or to retrieve the application on the card.
ISO/IEC 7816-5:2004 shows and defines how the uniqueness of application identifiers is ensured through the international registration of a part of this identifier.
ISO/IEC 7816-5 provides information on the following topics.
- the registration procedure,
- the competent authorities,
- the availability of the register linking the registered parts of identifiers to the relevant application providers.
The structure of the AID
The application identifier (AID) consists of two parts. The first part, the RID, is five bytes and identifies the organization providing the application. The remaining part, the PIX, is at most eleven bytes and distinguishes that organization's own products.
RID values are registered internationally, so two different organizations cannot use the same RID. Thanks to this structure, the terminal can select the AIDs it supports among the applications on the card.
In the chip payment flow, the terminal uses these identifiers when reading the card's file structure. That is why 7816-5 is one of the cornerstones of the EMV application selection process.
