Obviously, the simplest solution would be for the client to share their account details or add us as ‘team admin’, but that is not what this is about.
- Add us to your iOS Developer Program as ‘team member’.
- Create a ‘Distribution Certificate’, if you haven’t got one already.
- Create a ‘App Store Distribution Provisioning Profile’.
- Export the ‘Distribution Certificate’ assets and send the export and password to us. (For security sake, it’s a good idea to send us the password via other means than the exported certificate. E.g. by phone/SMS.)
- Ensure all relevant contracts have been signed.
- Create the application record in iTunes Connect. Ensure that the app record status in iTunes Connect is ‘Waiting for Upload’.
Might want to also ensure that they've agreed to all the latest T's & C's, particularly if the app is paid or has IAP. Getting blocked later in the process because they're missing is frustrating.