This article describes the process of accepting Master Service Agreement.

If you are the owner of the account you can accept Master Service Agreement for the newly created account by going to Active Accounts > Login in the Partner Portal.

Master Service Agreement

If you made one of the end users the owner of the account, use this page (https://controlpanel.msoutlookonline.net/asp/user/Login.asp) to log in with the owner's credentials to accept Master Service Agreement.