The National SAFEKIDS Campaign recommends that no child under the age of 12 be left at home alone. However, consider a child's age and maturity level. For example, if a child is extremely impulsive, it might be best to wait until he or she is older than 12.There appear to be very few states with specific regulations about the age of a child left at home alone.or example, if a child is extremely impulsive, it might be best to wait until he or she is older than 12. There appear to be very few states with specific regulations about the age of a child left at home alone.