This section describes the functionality needed in the IPS or IPS members to process Nexus payments. Some of this functionality is essential, while some is recommended or optional.
Purpose of the Service Level Description (SLD)
Nexus aims to connect local IPS systems in a seamless and transparent way. However, the various IPS systems around the globe are not designed according to the same standards and rules. For example, there are significant differences in:
The format of the primary account numbers
The types and formats of alias accepted
The maximum value that can be sent
How long after a payment can a dispute be issued
In order to facilitate payments in a transparent manner, Nexus will retrieve and store the local variations in a template file called a Service Level Description (SLD).
Each IPS will be responsible for defining its SLD and sharing it with Nexus, as well as updating Nexus when any details of the SLD change (for example, if the limit on payment size is changed). This update process uses the SLD API and is described in Setup: Synchronising SLDs.
As soon as the Sender selects the Destination Country, the Source Bank can retrieve the SLD for the Destination IPS. (See Step 1: Retrieving the SLD). This tells the Source Bank what information it must collect from the Sender.
Nexus will validate the requests from the Source IPS against the SLD of the Destination IPS and act accordingly. This means request which are invalid per the Destination IPS will be rejected by the Nexus Gateway.
Format of the SLD
Each SLD would define the following information. (See SLD API for more technical detail on the SLD format.)
2-letter country code e.g. SG
Whether IBANs are accepted in that country.
Local Account Number Format
Define the primary account number format (eg number of digits, format of bank identifier)
Local Bank Identifier Format
Define the format of local bank identifiers
Alias Conversion Available
Whether the Destination country supports aliases
A list of the alias formats (if any) that are accepted in the country
eg Email, Phone
Number of characters, letters, special characters etc.
Simple text that explains what this is, to be shown to the end-user
Maximum Value At Destination
The maximum value of a payment in the Destination Currency
Account Validation Available
Confirmation Of Payee Type
The model of Confirmation of Payee used: None, Comparison, Nickname or RealName
Screening Mandatory Fields
Defines any additional information, over and above the Nexus-mandated minimum, required by the Destination jurisdiction for sanctions screening.
IPS Mandatory Fields
List of Mandatory fields required by Destination IPS’s local payment instruction format
Timeout in seconds. Allows the Source Gateway to know if the Destination Gateway or Destination IPS has timed out. Can also be used to inform the Sender of the likely time to complete after clicking “Send Payment”
List of banks that are enabled to receive Nexus payments. Allows the Destination Gateway to check whether the Destination Bank is reachable.