The Nexus Scheme expects the IPSO (as operator of a Nexus Gateway) to take on the responsibility for connecting the local Nexus Gateway to the domestic proxy lookup service(s), particularly where:
The IPSO and the PLSO are the same entity, AND/OR
In each country that the IPSO provides payment services to, there is only one PLSO
Cases where there are multiple IPSOs or multiple Proxy Lookup Services in a particular country or jurisdiction may need to be handled differently. The approach to this scenario will be developed in a future phase of Nexus development.
IPSOs must adhere to the Nexus Scheme and become participants before they can process Nexus payments. However, the PLSO is not required (or able) to join the Nexus Scheme. Instead:
The IPSO must sign a bilateral agreement with the PLSO (or the scheme owner for the proxy lookup service, as appropriate)
This bilateral agreement must reflect the rules and obligations of the IPSO towards the PLSO and vice versa, as defined in the Nexus Scheme Rulebook, in order to ensure that the proxy lookup service is compliant with the Nexus Scheme.
The IPSO is responsible for verifying that the Proxy Lookup Service is compliant with the Nexus Scheme
Once an agreement is in place between the IPSO and the PLSO, the PLSO will provide the IPSO with API and security credentials that allow the Nexus Gateway to make proxy lookup requests on behalf of PSPs in other countries in the Nexus network.