ISO 8583 Specs

A simple credit card transactions sets off a flury of encoded data exchanges.

Every time someone swipes a credit or debit card, the exchange generates a series of coded messages that communicate a host of information about the card and its holder. The International Organization for Standardization (ISO) describes a widely used standard for these recorded transactions in its 8583 publication.

Messages and Codes

The first major standard in the ISO 8583 publication is Messages, Data and Code Values. This standardization is the most important for implementation of the exchange protocols and allows point-of-sale card readers to communicate with virtually any bank or credit card issuer around the world. Visa and MasterCard both deploy this standardization, which is proprietary and available either directly from ISO or from the American National Standards Institute. The code is not freely available online.

Institution Identification Codes

As its name implies, this second facet of ISO's 8583 exchange code contains standards by which a card reader can contact and identify a financial institution. Aside from the IIC's its ability to open communication with banks, the standard also contains software that allows credit card machines to verify the bank's identity and ensure a secure and encrypted transaction. Like the Messages and Codes standard, the IIC must be purchased and is not freely available.

Maintenance Procedures

This third bit of code in the ISO 8583 publication contains instructions that ensure the data sent during credit card transactions remains accurate and in tact. In general, data maintenance constitutes a rapidly growing field of software engineering, as data exchanges grow exponentially with world-wide access to high-speed Internet and online transactions become increasingly common. Card reader vendors might be inclined to rank this among the least important of the 8583 standards.

Standardization Goals

Standardization of credit card exchange protocols seeks to improve access to paperless exchanges essentially by encouraging financial institutions and credit card readers to speak the same language. Using French to tell an English speaker how many Euros are available in a Russian bank account would do none of the entities much good. With international data exchanges now the norm in commerce, ISO's 8583 publication helps to increase the likelihood cards will work virtually anywhere.

References

• Kuriositaet: ISO 8583 Introduction
• Kuriositaet: ISO 8583 Message Structure