The invention relates to a child safety seat (100) comprising a seat base (102) and a seat back (104), the child safety seat (100) being convertible between a backless booster configuration and a highback booster configuration, in the backless booster configuration a first side (106) of the seat back (104) providing the sitting area (114) of the seat and a second side (108) of the seat back (104) being opposite to the seat base (102), the first side (106) being opposite to the second side (108), in the highback booster configuration the seat base (102) providing the sitting area (114) of the seat and the second side of the seat back (104) providing a back rest of the seat.