Hi @david.plummer - Welcome to the community and thanks for reaching out to us.
We don’t provide an API that lists all the Services IDs under a given organisation.
In the scenario you describe using the user-restricted access mode, the referrals are not associated to the ODS organisation as such. The user is part of a workgroup which is associated to a service, and that relates to a referral. The service is part of the organisation but the access to view/manage a referral is controlled at the service level through e-RS workgroups or legitimate relationship (LR) as it’s also known as.
The Service Definer role in e-RS manages this process and would account for the flux in services and who needs access.
Similarly, the same role should be able to provide you with a list of Service IDs and any changes when they occur.
If you feel a new ‘Service ID’ endpoint would be a useful addition to our API, then please raise a new user request here.