The Law in WA
Birth to 6 months: Rearward-facing restraint (baby capsule). Must be in the back seat.
6 months to 4 years: Rearward-facing or forward-facing with built-in harness. Back seat required.
4 to 7 years: Forward-facing with built-in harness or booster seat. Back seat required.
7+ years: Must be in an appropriate restraint (booster or adult seatbelt if tall enough — generally 145cm).
Penalties
Incorrect restraint: $550 fine and 4 demerit points per child. Driving without any restraint: $550 fine per offence.
Choosing the Right Seat
Always buy new — never use a second-hand seat unless you know its full history. Look for the Australian Standard AS/NZS 1754 label. Get it professionally installed at a free fitting station (RAC, Kidsafe WA, or participating retailers).
Tips for Perth Parents
Never leave children in a parked car — Perth summer temperatures can make a car interior lethal within minutes. The back seat is always safest. Ensure the seatbelt isn't twisted and the harness is snug (you shouldn't be able to pinch the webbing).