You can invite additional people to manage the Google+ page of your business. A maximum of 50 managers can be assigned to each page and 20 people can be invited every day to manage the page.

This is how you can add a manager to a Google+ page:

  1. Log in to Google My Business and select the page you want to manage
  2. Click on the gear icon and select Settings
  3. In the top navigation menu choose Managers
  4. Click on Add Manager, enter their email address or invite by profile.
  5. Click on Invite

The page will show all the active managers and those who have been invited by you. When someone accepts the invitation, you will be notified through email. The owner as well as all the mangers can see the names and email addresses of all other invitees.