Once logged into the client portal you can update your main profile details.
On the left hand side under the "Your Info" section, is an "Update" button
Click on this to update your profile details.
You can also add a contact or edit an existing contact on the "Contacts" section.
To add a new contact click the "+New Contact" button.
You can then set the email preferences.
If you would like to give the contact their own restricted access to the Client Portal you can tick to Activate Sub-Account
Once this is ticked, you can then choose the permissions you would like the sub account holder to access.