ISO 8583 - Message Type Indicators

Summary

In this video, the focus is on understanding ISO 8583 messaging formats, which are essential for card-based transactions. The presenter walks through the anatomy of an ISO message, explaining its components such as the Message Type Indicator (MTI), bitmap, and data elements. Emphasizing the importance of each part, the video provides clear insights into how to interpret ISO messages and their meaning. By breaking down the first four digits of an ISO message, viewers will be able to identify the transaction type, its origin, and its purpose, which is crucial for accurately processing payments.

Takeaways

• 😀 ISO 8583 is a messaging standard used for electronic transactions, and understanding its structure is essential for payment processing systems.
• 😀 The ISO 8583 message travels between the acquiring and issuing systems, containing data about the transaction, card, and merchant details.
• 😀 The first part of an ISO message is the Message Type Indicator (MTI), which defines the type and purpose of the message.
• 😀 MTI is made up of four digits: the first represents the message version, the second indicates the message's purpose, the third defines its function, and the fourth identifies the source or origin.
• 😀 The message version is defined by the first digit of the MTI: '0' indicates the 1987 version, '1' the 1993 version, and '2' the 2003 version of ISO 8583.
• 😀 The second digit of the MTI specifies the purpose of the message, such as authorization (1), financial (2), reversal (4), and others.
• 😀 The third digit in the MTI indicates the message function, with values like '0' for request, '1' for response, '2' for advice, etc.
• 😀 The fourth digit of the MTI indicates the source of the message, with '0' representing the acquirer and '1' representing the issuer.
• 😀 The ISO message also contains a bitmap that signals which data elements are included, although the bitmap itself is not the focus of this lesson.
• 😀 Data elements in the ISO message contain key transaction details, including card information, transaction amount, merchant ID, and more, which are categorized and sent between the acquiring and issuing systems.

Q & A

What is the main goal of the video?

The main goal of the video is to explain the ISO messaging format, focusing on how to interpret and dissect ISO messages, specifically the Message Type Indicator (MTI) in the ISO 8583 message format.

What is the significance of ISO 8385 in relation to the video content?

ISO 8385 is mentioned as a previous topic covered in the channel, where concepts like acquire bank, issue bank, and credit card networks were discussed. The current video builds upon the understanding of ISO messaging formats discussed earlier.

What does an ISO message typically contain?

An ISO message typically contains card data (card number, cardholder information), terminal data (terminal number, merchant number), transaction data (amount, type of transaction), and additional dynamic information that institutions may send or receive to ensure accurate decision-making.

What are the three main parts of an ISO message?

The three main parts of an ISO message are the Message Type Indicator (MTI), the Bitmap, and the Data Elements. The MTI indicates the type of message, the Bitmap shows which data elements are included, and the Data Elements contain the actual transaction data.

What is the purpose of the Message Type Indicator (MTI) in an ISO message?

The Message Type Indicator (MTI) is the first four digits of an ISO message, and it provides information about the message's overall function, such as whether the message is for authorization, financial transactions, file updates, etc.

How does the version of ISO 8583 affect the message structure?

The version of ISO 8583, which can be 1987, 1993, or 2003, affects the positioning of data elements within the message. The version is indicated by the first digit of the MTI, and it is important to ensure that both the acquirer and issuer agree on the same version to avoid misinterpretation of data.

What does the second digit of the MTI represent?

The second digit of the MTI represents the purpose of the message, such as authorization, financial transactions, reversal, reconciliation, etc. This digit ranges from 1 to 8, with 9 reserved for ISO-specific purposes.

What are some examples of purposes indicated by the second digit in the MTI?

Examples of purposes indicated by the second digit in the MTI include: 1 for authorization, 2 for financial transactions, 3 for file updates, 4 for reversals, 5 for reconciliation, 6 for administrative messages, and 7 for network messages.

What does the third digit of the MTI represent?

The third digit of the MTI represents the function of the message, such as whether it is a request or a response. For example, 0 indicates a request, and 1 indicates a response.

How can you interpret an ISO message from its MTI?

By examining the first four digits of the MTI, you can determine the version of the ISO message (first digit), the purpose of the message (second digit), the function of the message (third digit), and the source of the message (fourth digit). For instance, '0200' means a financial request in the 1987 version coming from the acquirer.