How tall do you have to be to sit without a booster seat UK?

In the UK, children must use a booster seat until they are 135 cm (4 feet 5 inches) tall or until they reach the age of 12, whichever comes first. Once they meet either of these criteria, they can sit in a regular car seat without a booster. It's important for safety that the vehicle's seat belt fits properly across the child's shoulder and lap. Always check the specific regulations and guidelines, as they may vary.