Unsync my new phone from old iPhone
I’d like to unsync my new iPhone 13 Pro from my old iPhone 6s
as all data has been transferred over
and I’d like to resell old phone but want to make sure I don’t disrupt my new iPhone 13 pro
iPhone 13 Pro, iOS 16
Question marked as
Follow this support article on your old phone. It will not affect your new phone at all. You obviously won't have to do the step to back up your data, since you have already transferred it to your new phone. Don't forget to do the last step to remove your old device from your list of trusted devices.
What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support