A merchant Account is the relationship between one Profile and one host organization. The host organization is the organization that owns or hosts the relevant product instances; it is not the seller's party.
Account = Profile × Host Organization
The account carries host-level approval, onboarding, status, and platform capabilities. This means the host can establish one governed merchant relationship and then allow that account to enroll into one or more product instances it owns.
Cardinality
There can be only one current account for the same profile and host-organization pair. Closed or rejected history can remain, but two pending/active/suspended relationships cannot coexist for that pair.
An account does not own listings or storefronts. Those are isolated through Enrollment.