I'm the Team Agent of an iOS Enterprise Program.
I'm trying to add a new app id (the new app-id is never used before in my account, but it's possible it is used by another enterprise account. But, after submit, it says:
The bundle identifier you have specified is already in use. Please
select another.
Why it is happening and how can I solve this?
App IDs must be globally unique (not just unique within your iTunes account).
If you or somebody else has used that bundle ID on another iTunes account, Enterprise or regular, then it can't be re-used on any other account.
To avoid this, it's best to use wildcard ids for development (com.mycompany.*) and only create fully qualified ids when you are ready to deploy an app using a specific account.
Bundle Identifiers need to be unique across the board. If it's used in another business just change it. You can do this in the *-Info.plist file associated with your project. Look for the Bundle identifier field. It's reverse domain typically. So use something like com.yourcompany.appname If the bundle wasn't set by you but, someone on your project. You should be able to get access to a provisioning profile that supports that bundle identifier. Keep in my mind for all purposes that iOS will treated different bundle identifiers as different apps.
All app ID's seem to have to be unique among all IDs that Apple had in their entire worldwide iTunes database.
Has some other company registered the internet domain for mycompany.com, which you used as part of your com.mycompany.myapp app ID? Did you substitute your company's domain name for "mycompany". Or perhaps some other company is trying to (mis)use your company's registered domain name. Or does your company's corporate unbrella encompass more than one developer account (perhaps 1 enterprise enrollment and 1 company enrollment, or more)? The app ID could be registered in the other account.