1. Register at Apple to get an Apple ID. Or check if your organization has an Apple ID already on the Apple support pages.
   
   
2. Register for a D-U-N-S number on the Apple D-U-N-S registration page. The D-U-N-S numbers are managed by Dun & Bradstreet and for free.
   
   
3. Register for the Apple Developer Program. The membership costs $99 per year.
   
   
   
   Within a few days following the registration, Apple will probably call you and ask you a few questions to ensure that your intentions for the app are in line with the Apple guidelines. Here are some possible questions and some ideas for your answers:
   • Q: What's the name of the organization that registers?
     A: The name will be the same that was used to register for the D-U-N-S number.
   • Q: In which department does the contact person work?
     A: Just state the department where you (the contact person for Apple) work.
   • Q: What is the purpose of the app?
     A: To comply with Apple's guidelines your app needs public relevance. You can easily create public relevance by explaining that your app will contain valuable information for a widespread and public audience. For example, you can post job vacancies for potential new employees, organization news for partners and customers, and offer additional information for employees that will be available after signing into the employee space.
4. Sign in to App Store Connect with your Apple ID to verify that everything works correctly.
   
   

Additional helpful information: 

• Apple explains the D-U-N-S number