What does SUPP mean in ISO 20022?

SUPP is Supporting Document in the ExternalLetterType1Code code set: Document is a supporting document.

Where does SUPP appear in a message?

For example in auth.026, element ReqOrLttr/Tp/Cd.

ExternalLetterType1Code

SUPP Code: Supporting Document

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

SUPP means supporting document in the ISO 20022 letter type code set. Document is a supporting document.

Code: SUPP
ISO name: SupportingDocument
Status: Registered
Last updated: 2021-11-30

Official definition

Document is a supporting document.

Definition from the ISO 20022 External Code Sets, 2Q2026 (published 28 Aug 2026).

Messages and fields that use ExternalLetterType1Code

Message	Element path
auth.026	ReqOrLttr/Tp/Cd

SUPP in other code sets

SUPP questions

What does SUPP mean in ISO 20022?: SUPP is Supporting Document in the ExternalLetterType1Code code set: Document is a supporting document.
Where does SUPP appear in a message?: For example in auth.026, element ReqOrLttr/Tp/Cd.

All ExternalLetterType1Code codes · ISO 20022 code sets

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