NIM39305 - National Insurance Numbers (NINOs): Registration of a new NINO: Juvenile Registration: the automatic process
Most people are automatically given a National Insurance Number as they approach the age of sixteen. 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. From the child reaching age fifteen years and nine months, HMRC notifies each child of their NINO.
However, special action needs to be taken for: