What if there are not enough seat belts available?
Seat belt wearing law does not prevent you from carrying more adult passengers than there are seat belts.
However, children up to 135cms in height must have child restraints with few exceptions. Nevertheless, the way in which passengers are carried must not cause danger to any person in the vehicle. Do not overload a vehicle. If you have adult passengers without a seat belt remember that they can cause injury to others in an accident.
Children 3 years and over can only travel in the back of a vehicle without seat belts (e.g. a classic car) and those under 3 years cannot be carried at all.