A D-U-N-S number is an international business number issued by Dun & Bradstreet. Apple uses this to identify organizations.

To apply for a D-U-N-S number, use the following form at Apple: https://developer.apple.com/enroll/duns-lookup/

​You may be asked to sign in to continue. If you have an Apple ID (even a private one), you can sign in with that. It is actually best to use your personal Apple ID throughout the process because it must be verified. Your developer account is not tied to your Apple ID.

If you don’t have an Apple ID, you can create one here: https://appleid.apple.com/account

The link for the DUNS application will take you to the following page:

Enter your organization's information and press Continue.

You will probably then receive a message that your organization was not found. Go to the bottom of the page and select (Submit).

You should now first receive an email that your application has been received. About a day later you should receive another email that your application has been completed. It will also tell you what your D-U-N-S number is.

If you do not receive an email about your D-U-N-S number within a few days, you should contact Dun&Bradstreet support: https://support.dnb.com/?CUST=APPLEDEV

​Furthermore, when you have received your D-U-N-S number From the time you receive your D-U-N-S number, it can take 2-14 days before Apple receives information about the number.

So after a maximum of 2 weeks, you can continue with the following guide: Apply for a Developer Account