NIM39305 - National Insurance Numbers (NINOs): Registration of a new NINO: Juvenile Registration: the automatic process
Most people are automatically given a number as they approach age 16. This is because when a claim to Child Benefit is made, the child is allocated a Child Reference Number (CRN) for HMRC/DWP use only. When the child reaches 15 years 9 months, HMRC notifies each child of their NINO.
However, special action needs to be taken for