Following this thread to learn from other families.
We have a 4th grader who is interested in her own phone -- though she knows us well enough to know her first phone will not have internet access. She's begging for a flip phone to start. At her school (which is private, high-income families), about 50% of her 4th - 5th grade classmates have phones, but most of them are not smart phones. Her school does not allow elementary or middle schoolers to have their phones out/about during the day.
Our current thinking is:
1) Flip phone "emergency" phone that lives at the house beginning soon - this would NOT be "her" phone, but would allow us to continue teaching her how to be safely at home alone
2) waiting until middle school for a non-screen/internet phone,
3) waiting until high school for a smart phone
We also do NOT have a landline phone and thus, the phone becomes a limiting factor as we're gradually teaching her how to begin to stay at home alone for short periods of time (have only done 15 min trips within the neighborhood so far - such as picking up the dog from the dog sitter's house, etc.). As she moves to age 10 - 11, we want to gradually lengthen the time she can spend at home alone. We've bought her the American Girl "Staying Home Alone" book to begin those discussions, and right now she does know basics like how to call the police via a button on our home alarm system, knows three neighbors well enough to knock on their doors during an emergency, and we've started discussions about what our daughter would be allowed to cook/watch/do when we're not home, etc. All this is a bit premature since we're not regularly leaving her alone yet, but we're building the knowledge base/expectations for her now.
Since phones invariably bring up issues around mental health, FOMO/social media, sexuality, etc. - we're beginning a sexual health program/curriculum this year (the OWL - Our Whole Lives program, which is not abstinence only based, but is age appropriate and has kids focus on developing/reflecting on their personal and family values). It's super hard for parents (of any belief system) to imagine our kids getting old enough to deal with issues related to self esteem or sexuality, but we're trying to face it head-on and stay "askable" parents.
I'd also recommend the American Girl book on "Digital World" safety and beginning online safety conversations EARLY. Our daughter is pretty well versed on these issues but we continue to build on them. IE, she has a firm understanding that its not safe to "friend"/talk with/etc. "strangers" online, but we have also discussed the more likely scenarios, such as a friend or peer asking her for photos, etc. This article is an important one for both parents of boys and girls:
https://www.amightygirl.com/blog?p=22076In other words, in addition to telling our kids (boys and girls!) DO NOT SEND SELFIES/NUDES, we also need to be telling them, IT'S NOT OK TO ASK/PRESSURE SOMEONE TO SEND YOU A SELFIE/NUDE PHOTO. When I talked with my daughter (in an age appropriate way) about how as she gets older, digital safety and sexual pressure is less likely to come from strangers, but rather from a boy/girl she likes or respects, it helped us both to envision the ways she could respond.