Having a Google AdSense account is a technical requirement for creating an Ad Manager account.
Already have an AdSense account?
Yes
No
Please sign up for an AdSense account below.
It may take up to one week to have your AdSense account reviewed. Once you've received your AdSense approval email, please return to Google Ad Manager and log in using your AdSense username and password. After you log in to Ad Manager for the first time you can invite additional users to join your Ad Manager account.