Version Conversion

from iso8583sim.core.builder import ISO8583Builder
from iso8583sim.core.convert import convert_message
from iso8583sim.core.parser import ISO8583Parser
from iso8583sim.core.types import ISO8583Version

parsed = ISO8583Parser().parse(raw_1987_message)
result = convert_message(parsed, ISO8583Version.V2003)

raw_2003 = ISO8583Builder(version=ISO8583Version.V2003).build(result.message)

result.notes     # Things worth checking, e.g. fields whose meaning changed
result.dropped   # {field_number: reason} for fields that could not be carried over
result.lossless  # True when nothing was dropped

What changes

Item	Rule
MTI	The first digit is the version: `0` (1987), `1` (1993), `2` (2003). `0200` becomes `1200` or `2200`.
Original data elements	Moved from field 90 (1987, fixed 42) to field 56 (2003, LLLVAR) and back, unless the destination field is already set.
Other fields	Checked against the target version’s definition and kept when they fit.

What gets dropped

Fields are dropped, never truncated, and each drop has a reason in result.dropped:

Field 52 (PIN data) when the PIN block size differs (8, 16 or 32 bytes). A PIN block can’t be padded to a new size. Re-encrypt it for the target version, for example as a format 4 block with iso8583sim.security.encrypt_pin_block.
Field 53 (security control information) when its definition differs.
Fields 64 and 128 (MAC). The MAC covers the whole message, so it must be recomputed after conversion with ISO8583Builder.build_with_mac.
Values that don’t fit, such as a 60 character field 43 converted to 1987, where field 43 is a fixed 40 characters.
Fields not defined in the target version.

Notes

Fields 57 to 59 are reserved in 1987 but have defined meanings in 2003 (for example, field 57 is the Authorization Life Cycle Code). Their values are carried over, with a note to check that the value still means the same thing. A message converted to another version and back reproduces the original exactly, as long as nothing was dropped.

CLI

iso8583sim convert "0400..." --to 2003

See the CLI reference.

Get started

Core

Card networks

Tools and interfaces

LLM features

Architecture

Operations

What changes

What gets dropped

Notes

CLI

​What changes

​What gets dropped

​Notes

​CLI

What changes

What gets dropped

Notes

CLI