Abstract A boundary layer of finite thickness separates the magnetosheath and the magnetosphere. Within this boundary, we have the outer lowâlatitude boundary layer (LLBL), the magnetopause current layer, and the inner LLBL. Earlier works point out that the interface on which KelvinâHelmholtz Instability (KHI) develops has implications for how effective this mechanism is in transporting solar wind mass, momentum, and energy into the magnetosphere. We provide evidence that the KHI begins developing between the inner LLBL and the magnetosphere and can continue to grow to form rolledâup vortices. The KH waves developing in the inner edge can grow in amplitude and become as large as the boundary layer itself, thereby enabling the transport of the magnetosheath particles into the magnetosphere. We outline possible scenarios for KH wave growth in this multilayered boundary layer and discuss the observational evidence for the presented scenarios.