Abstract: A booster seat includes a seating element which defines an outer seating surface, and a substantially hollow inner region with an opening through which access to the inner region is enabled. At least one seat belt engagement element is mounted on the seating element, rotatable between a deployed position in which the or each element is adapted for releasable engagement with a seat belt, and a stowed position in which the or each element is located above the outer seating surface of the seating element, so as to provide an uneven and unacceptable surface for sitting such that a user would be encouraged to deploy the seat belt engagement elements.