Posted 1/9/2018 10:55 (#6491499 - in reply to #6473217) Subject: No earlier than 12
12-13 is a good age. We got our kids Virgin Mobile plans @ $35/mo and $100 Virgin Mobile smartphones - their androids, but older version of the OS.
When they hit 16 they pay for the phone's service themselves - they can do whatever they want for service, but all have surprisingly stuck with the $35/month when they had to pay for it.
Like most kids they don't call much - mostly texting and apps.