As your kids get older they begin to broach the conversation of when they can have a phone of their own. After all, Mom and Dad have one, or an older brother/sister and possibly even some kids in their class. Receiving a smartphone is a milestone in their life.
Providing a smartphone to your child should never be done without serious conversations. Not a conversation on the day the smartphone is provided, but multiple times over a period of multiple years.
In the same way that you don’t hand your kids the keys to a car without any training and simply say “Good luck,” you shouldn’t hand them a smartphone and say, “What could go wrong?”
FamilyLife has a great article on how to enjoy, leverage and self-regulate your phones.