A bundle identifier is globally unique across the whole Apple ecosystem, not just within your team. Once any developer anywhere registers com.example.app, nobody else can, and Apple will not tell you who has it. This trips people up because the equivalent identifier on Android only has to be unique on Google Play.
The likely causes, in order
- You already registered it yourself
- Under a personal Apple ID before joining the company team, or in an old account. This is the most common case by a wide margin, and the most annoying, because the portal for your current team shows no sign of it.
- A colleague registered it
- On a different team than the one Xcode is currently signed in as. Check with whoever set up the original project.
- A genuinely unrelated developer owns it
- Common with obvious identifiers like com.company.app or anything using a domain you do not control. You cannot reclaim these.
- A wildcard App ID is blocking it
- An existing wildcard such as com.example.* can prevent registering a specific ID beneath it in some configurations. Look for wildcards in your Identifiers list.
If it is one of your own accounts
- 1
Sign in to the Apple Developer portal with every Apple ID you have used
Including personal ones from before you joined the team. Go to Certificates, Identifiers and Profiles, then Identifiers.
- 2
Find the App ID and check whether it is in use
If no app on App Store Connect is using it and no active profile references it, it is safe to remove.
- 3
Delete the registration
Select the identifier and remove it. Deletion is permanent and any profile referencing it stops working immediately.
- 4
Wait, then retry
Availability is not always instant. Give it a few minutes before trying to register on the new team.
If you need to pick a new one
Reverse-DNS on a domain you actually control is the convention and the thing least likely to collide: com.yourdomain.appname. Avoid com.example, com.test, com.myapp, and anything with your framework's default placeholder still in it.
The same error with a different cause
If the identifier is definitely unused, check whether your account has permission to register App IDs at all. The Developer role on a team account usually cannot, and Xcode reports the resulting refusal with the same wording. An Account Holder or Admin can register it for you. See App IDs for how App IDs, bundle IDs, and wildcards relate.