Texas law requires all children younger than 8 years old, unless taller than 4'9", to be in the appropriate child safety seat system. Booster Seats: Use a belt positioning booster seat when your child's weight or height is above the forward-facing limit for the car seat.Texas Seat Belt Laws. One of the child's primary caregivers must get registered and attend the hourlong class. Find out car seat laws and booster seat laws in every state and make sure your child is strapped in according to national and state safety standards. In New York, children should remain in a booster seat until at least age 8. Children in booster seats should remain in the back seat. Children under eight years of age, weighing under 100 pounds, and shorter than 4'9" need to use a booster chair in the backseat. This is the most up to date and accurate list of state car seat laws. We review each state's car seat law statute every year.