UK- child car seats: the law https://www.gov.uk/child-car-seats-the-rules/when-a-child-can-travel-without-a-car-seat2. When a child can travel without a car seatA child can travel without a child car seat in some circumstances.Taxis and minicabs (private hire vehicles)If the driver doesn’t provide the correct car seat, children can travel without one - but only if they travel on a rear seat:and wear an adult seat belt if they’re 3 or olderwithout a seat belt if they’re under 3