Under the Children Act 1989, a person with parental responsibility must normally consent to medical treatment for a child. In emergencies, a doctor can treat without consent. A written consent form allows a trusted adult to authorise non-emergency treatment when parents are unavailable.

• Anyone with parental responsibility can consent to treatment
• A written consent letter enables a trusted adult to act in parents' absence
• Does not replace parental responsibility — it delegates limited authority
• Emergency treatment: doctors can always treat in a life-threatening emergency
• NHS: a parent's signed letter is usually sufficient for GP visits and minor treatment

Legal reference: Children Act 1989; Family Law Reform Act 1969 s.8; General Medical Council guidance