Message translation and transformation
Where an IPS community (a) does not support ISO 20022, or (b) uses fields differently than defined in the Nexus standard messages, then the IPSO is responsible for translating messages:
- before they are sent to Nexus
- after they are received from Nexus
Nexus expects and will only accept the Nexus-standard ISO 20022 messages.
Some messages need to be transformed by Nexus after they are received from the Source IPS and before they are sent to the Destination IPS (or vice versa).
Transformation varies depending on the message type but may involve:
- Moving the agents in an instruction (eg changing the Instructing and Instructed Agents after the first leg of the payment has been processed in the Source IPS)
- Converting a currency and payment value from the Source Currency to the Destination Currency (according to the Nexus quote ID provided in the message)
- For the proxy lookup message (camt.023), replacing the ID of the Assignee
In some cases, an IPS community will require the use of certain fields that are not mandatory in the standard Nexus messages. For example, a jurisdiction may require the use of Category Purpose codes for each payment, for regulatory reporting or compliance reasons.
An IPS can define Mandatory Fields that are required in its community. These Mandatory Fields are included in the reference data provided to a Source PSP when it is initiating a payment, and informs the Source PSP that additional fields are mandatory beyond the basis Nexus standard.
Mandatory fields can be defined for any message type, using the Admin Portal.