ISO 20022 · External code set

Letter type codes

Specifies the letter type as published in an external letter type code list. External code sets can be downloaded from www.iso20022.org.

3 registered codesSource release: August 2026 (v3)
Registered codes in ExternalLetterType1Code. Select a code for its full definition and source details.
CodePublished name and definition
LFBKLetter From Bank

Document is a letter from the bank.

LTBKLetter To Bank

Document is a letter to the bank.

SUPPSupporting Document

Document is a supporting document.

Message references 2

Versions listed in the source workbook, including older versions. This list does not establish which messages a bank, network or provider supports.

  • auth.026.001.03Currency Control Request Or Letter V03
  • auth.026.001.04Currency Control Request Or Letter V04

Source: UsageInMsgs sheet in 2Q2026_externalcodesets_v3.xlsx.