Dreaming of lost phone is a warning sign as per dream interpretation and meaning. The dream means you are allowing yourself to get into troubles with your bad decisions and unwanted desires. It also means you are not ready to let go something you know is lost forever. Dreams of lost phone also means partial recovery of something you had lost but it is worthless now.
Dream of lost phone and you are seen in the dream means you will solve a crime that had happened to you. It also means you will identify the thief and recover what was stolen.
Dreaming of lost phone and you are not in the dream means something that you had valued or loved will not be recovered. What is lost is lost and you need to accept it.
A dream of lost phone and it is returned back to you means hope and love. It also means help from strangers or a new relationship.
Please note that a dream to have meaning it should happen without a daytime influence. Dreaming of phone after intense daytime activity about it has no meaning.