ISO 8583 is an international standard for financial transaction card originated messages. It defines the interchange message format and content between automatic teller machines and payment card networks. The standard specifies a message type identifier, bitmaps to indicate included data elements, and up to 127 data elements containing transaction details. An ISO 8583 message facilitates electronic payment processing by transmitting necessary information through a network.

1. ISO 8583 Basic
Presenter: Hieu Minh Nguyen

2. ISO8583

Financial transaction card originated messages
Interchange message specifications is the International
Organization for Standardization standard for systems
that exchange electronic transactions made by
cardholders using payment cards

The objective of this protocol is to transmit information
for payment processing through a network, usually
using TCP/IP sockets. An ISO8583 message can have
up to 63 or 127 fields and is processed in a linear way,
that is, the message can be processed as it is being read.

3. Structure ISO8583

We can separate the message into 3 parts:
− Message Type Identifier(MTI)
− Bitmaps
− Data Elements

4. Message Type Identifier

Message Type Identifier or MTI is 4 digits numeric
that describe the message type. It will explain the
message function.
− ISO 8583 version
− Message class
− Message function
− Message origin

5. ISO 8583 version

Position one of the MTI specifies the versions of the
ISO 8583 standard which is being used to transmit
the message.

6. Message class

Position two of the MTI specifies the overall
purpose of the message.

7. Message function

Position three of the MTI specifies the message
function which defines how the message should
flow within the system.

8. Message origin

Position four of the MTI defines the location of the
message source within the payment chain.

9. Message Type Identifier(Example)

10. Bitmaps

Within ISO 8583, a bitmap is a field or subfield
within a message which indicates which other data
elements or data element subfields may be present
elsewhere in a message.

A message will contain at least one bitmap, called
the Primary Bitmap which indicates which of Data
Elements 1 to 64 are present. A secondary bitmap
may also be present, generally as data element one
and indicates which of data elements 65 to 128 are
present.

11. Bitmaps(Example)

12. Data elements

Data elements are the individual fields carrying the
transaction information.

Each data element has a specified meaning and
format, the standard also includes some general
purpose data elements and system- or country-
specific data elements

Each data element is described in a standard format
which defines the permitted content of the field
(numeric, binary, etc.) and the field length (variable
or fixed)

13. Data elements

14. Data elements

Additionally, each field may be either fixed or
variable length.

15. Data elements

16. ISO 8583 Example

Examples Message
210040300041808100000599501100000000001200
805020723006015070000000070112222ABC00000
000000010190000000530000000001

The components that form it, and the results are
bitmap consists of 16 bit characters cause the first
bit of the decimal 7 (0100) is ’0 ‘so identified
without secondary bitmap

17. ISO 8583 Example

The components that form it, and the results are as
follows:

18. ISO 8583 Example

Each character in the
bitmap in-unpack into 4
binary characters.

These elements exist in
the data-elements are
elements to: 2, 11, 12, 26,
32, 33, 41, 48 (Position of
value “1″is read from left
to the right column to
unpack binary)

19. ISO 8583 Example
Each position is worth ’1 ‘at the
unpacked-Bitmap have data
elements that correspond to
components of data-
elements.Data elements:
05995011000000000012008050
207230060150700000000701
07
12222ABC000000000000101
90000000530000000001