ISO 20022 ASN.1

ISO 20022 ASN.1 physical syntax, an alternative to XML.

Definition

ISO 20022 separates the logical message model from its physical representation. Part 3 standardises the XML syntax (XSD); part 4 standardises the ASN.1 syntax, which enables a compact binary encoding (e.g. PER) of the same content — useful for card payments and bandwidth-constrained environments. Both syntaxes derive from the same UML model in the Repository.

Origin

Standardised by ISO 20022-4 (“ASN.1 generation”), part of the ISO 20022 series published by ISO TC 68/SC 9; ASN.1 itself is defined by the ISO/IEC 8824 series.

Example in context

A card authorisation message (acquirer ↔ issuer, the caaa family) may be carried as XML or, via ISO 20022-4, encoded in ASN.1/BER or PER to reduce payload size at the terminal.

Related terms

• ISO 20022 — the framework standard (model + syntaxes).
• ISO 20022 Repository — common model behind XML and ASN.1 syntaxes.