have someone’s number—(coll.) know smb.’s real motives or intentions when dealing with that person:
- “I think I’ve got your number, Mr. Omnipotent Superbeing,” she said gently, “You don’t fool me for a minute.”
have someone’s number on it—(of a bomb, bullet, etc.) be intended by fate for a particular person (also: have someone’s name on it):
- If it’s got your number on it, you’ll get it, no matter where you are.