Q. [Expo ID Registration] It says that the Expo ID I want to use is already in use. A. The Expo ID you entered is already in use by someone else and you cannot register that Expo ID. Please register another Expo ID. Related articles [Expo ID Registration] What characters should I use for my Expo ID? [Expo ID Registration] Is there a specific format for the password? [Expo ID]Can I change my ExpoID? [Expo ID Registration] This email address is duplicated with the email address currently registered by proxy registration. [Expo ID Registration] My email address is already registered to an Expo ID so I cannot register a new one.