I have multiple GMP accounts. How do I set the primary account?
The primary account is the one that will display first when you log into My Account. You can switch between the account your viewing with clicking or tapping on the “Switch Account” link under the service address at the top of the page.
In this switch account panel, each account you have is represented by a box with the account nickname and service address. To switch which account is the primary one, click on “Make Primary” in the box for the account you’d like.