However, if you change your name, a person with parental responsibility, may apply to the court to have it reversed, and the court will have to determine whether you are mature enough to understand the consequences.
In most cases a court will uphold your deed poll unless there are very good reasons not to.
Children under the age of 16 cannot change their name themselves. Only persons with parental responsibility can do this. If two people have parental responsibility both persons need to consent.
If one of the persons with parental responsibility does not consent, then you cannot change a child’s name without a court order.