Abstract: A vehicle seat assembly having a seat back, a seat bottom and a headrest coupled to the seat back and slidably moveable between a lower position against the seat back and an upper position spaced above the seat back. A child restraint seat is recessed in the seat back and pivotal between a folded position against the seat back and an unfolded use position extending downwardly against the seat bottom. An interlocking member includes a support housing for slidably receiving the headrest and a latch coupled to the support housing interacts between the headrest and child seat for locking the child seat in the folded position in response to the headrest being raised to any selective position above the lower position and unlocking the child seat to allow pivotal movement to the unfolded use position when the headrest is in the lower position.