Here is what the State of Texas says..
How old must a child be to be left home alone?
Answer: Supervision of children is basic to the prevention of harm. Adequate supervision means an adult caregiver is accountable for the child's care. Although, there is no Texas law that defines a specific age at which a child may be left home alone, there are several factors that should be taken into consideration when deciding how closely to supervise a child, including:
* the age, emotional maturity and capability of the child;
* layout and safety of the home, play area, or other setting;
* neighborhood circumstances, hazards, and risks;
* the child's ability to respond to illness, fire, weather, or other types of emergencies; and
* whether the child has a mental, physical, or medical disability.
The number of children left unsupervised, the accessibility to other responsible adults, the length of time or frequency with which the child is left alone, and the child's knowledge of the parent's whereabouts are additional relevant factors.
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It depends on the child. Our daughter would stay home while I ran to the grocery store when she was 9. We worked up to a little longer each year.
They need to know 911, trusted neighbor phone numbers. I also told her to never answer the door if anyone knocked. And not to go outside or invite a friend over.
She also knew not to use the stove or oven.
Now that we have cell phones, I am sure your child could call you immediately and you would feel a lot more secure than I did..