Identity and customer are different
A person signs in with an identity. A customer record represents the business context they are working in. Membership connects the two.
Make switching visible
Show the active customer in your application. When the person switches, update the interface and subsequent requests to use that selected context.
Carry the context into requests
Use the supported customer path or X-Customer-Id context for the operation. Confirm the membership and permission requirements in your integration.
Keep records scoped
Orders, subscriptions, and custom application data should be presented for the selected customer. Handle a missing or unauthorized context before showing business information.