Children who are passengers in a vehicle must use a child restraint. This is a national legal requirement which came into force in September 2006. The term "child restraint" is the collective term in the seat belt legislation for baby seats, child seats, booster seats and booster cushions.
All children up to 135cm tall (around 4'5"), or the age of 12, whichever comes first, seated in the front or rear of cars, vans and other goods vehicles must travel in the correct child restraint for their weight with very few exceptions.
It's important that your child restraint fits well. Checking the fit of your child's car seat every journey could save their life or protect them from serious injury.
These organisations have detailed guidance about the use of child restraints: