What is the difference between MT759 and MT799?

Both carry trade information for which no specific message exists. The MT799 is free text only; the MT759 adds coded fields for the form of undertaking and the function of the message, which makes it easier to route and process. Swift designed the MT759 to replace the MT799, but its use is optional.

Can a guarantee be issued with an MT759?

Guarantees and standbys are issued with the MT760. Industry guidance recommends the MT759 for undertakings that cannot be issued in the MT760 format, by agreement between the banks.

Category 7: Documentary credits, guarantees and standby letters of credit

MT759 Ancillary Trade Structured Message

Written and maintained by ZagTrader. Last reviewed 21 October 2026. How this page is sourced and checked

The MT759 is a structured message for exchanging information about an existing trade transaction, such as a documentary credit, demand guarantee, standby or other undertaking, when no specific message type exists. Examples are a fraud alert or a financing request. It is meant to be used instead of the free format MT799.

Message type: MT759
Category: 7
Status: In the current standard
ISO 20022: No direct equivalent

What MT759 is used for

Swift added the MT759 to the documentary credit messages in the November 2018 release and reworked it with the guarantee messages in November 2021. Unlike the MT799, it identifies the form of undertaking with a code (field 22D) and what the message is for with a function code (field 23H), followed by the narrative, so the receiving bank can route it without reading free text first.

The rule is to use a dedicated message where one exists: an amendment is an MT707 or MT767, a refusal an MT734 or MT786. The MT759 covers what is left. Since 2021 it is also the recommended message for issuing or amending undertakings that the structured MT760 cannot carry, such as some dependent undertakings. Using it remains optional, so many banks still receive MT799 messages for the same purposes.

Sent by: Any bank party to the trade transaction
Sent to: Another bank party to the same transaction

Fields

This is a catalogue entry: the field-by-field structure is not shown here because we publish structures only where we have checked them against public sources. Paste an MT759 into the parser to see each field decoded with its tag, name and value.

Decode an MT759 in the parser

ISO 20022

No ISO 20022 equivalent in general use. Category 7 messages were not part of the November 2025 ISO 20022 migration and the MT759 is still exchanged as MT on Swift.

MT759 questions

What is the difference between MT759 and MT799?: Both carry trade information for which no specific message exists. The MT799 is free text only; the MT759 adds coded fields for the form of undertaking and the function of the message, which makes it easier to route and process. Swift designed the MT759 to replace the MT799, but its use is optional.
Can a guarantee be issued with an MT759?: Guarantees and standbys are issued with the MT760. Industry guidance recommends the MT759 for undertakings that cannot be issued in the MT760 format, by agreement between the banks.

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