Owners and Admin+ can already add, edit or delete cards, pay invoices, purchase credits or change the subscription. But if they want to give those privileges to another user on the account, they can easily do that.
Step 1: Log in and click your name in the top right corner of the screen. *ONLY Owners and Admin+ users have the access to grant Admins billing privileges.
Step 2: Select "Users" from the drop down menu
Step 3: Click the pencil icon next to the user you want to give these privileges to
Step 4: Scroll down to the bottom of the screen and click the box with "Allow User to Manage / Pay with Credit Cards on File" next to it and then click "Save".
You have now given that user permission to manage and pay using the credit card on file. For instructions on how you can add a card on file, click HERE.
To edit the email address your invoices are sent to, click HERE.