Interface Regimes and Phenomenological Accessibility

Physical phenomena are accessible only through specific observational and inferential interfaces.This work introduces the concept of Interface Regimes (IR) as a structural condition for phenomenological accessibility, independent of the underlying physical ontology. An interface regime specifies the operational constraints under which physical states can appear as phenomena, namely through physical coupling, trace persistence, comparability, and partial invertibility of the observational mapping. The absence of a signal is therefore not interpreted as evidence of ontological absence, but as a possible consequence of inactive, collapsed, or incompatible interface regimes. The framework introduces no new physical entities and does not modify existing dynamical laws. Instead, it isolates necessary conditions for phenomenicity, comparability, and non-arbitrary closure in physical description. Clockability (operational time) is shown to arise as a specialized regime of IR, while residual inconsistencies across heterogeneous observational domains are interpreted as a structural consequence of non-invertible interfaces.