If a channel is linked to a Brand Account, multiple people can manage it from their Google Accounts. You don't need a separate username or password to manage YouTube channels with a Brand Account.

First, check to see if your channel is already connected to a Brand Account:

1. Go to www.youtube.com/account_advanced. You may need to sign in first. 
2. Check under "Account information" for one of the following:
   • If you see the message "You are the owner of this channel and the connected Brand Account," you have a Brand Account. You can now follow the instructions to change channel owners and managers.
   • If you don't see the note or an option to add managers, you need to create a new Brand Account or associate your channel with an existing Brand Account. 
   • If you know you have a Brand Account, click your account icon in the top right and make sure you're using the right account.

* Nguồn: Youtube