How to prepare my iPhone to sell it?
How to prepare to sell
[Re-Titled by Moderator]
iPhone 6
Question marked as
See this Apple article: What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch
https://support.apple.com/en-us/HT201351
Then remove from your account, see this Apple article: Check your Apple ID device list to see where you're signed in