If the invitation to the user you are adding as a Joint Owner of a Personal Capital Cash account has not received their invitation after a few hours, there are few steps you can take.
First, make sure that you have sent the invite to the right email address- is it spelled correctly, and is the email client (gmail, yahoo, hotmail, etc) correct?
Advise your invitee to check their spam folder for an email from email@example.com as it may have been filtered.
If you have checked each of these and still do not see the invitation, try resending the invitation through your dashboard. From your settings menu, scroll down to the Additional Users section. Next to your invitee's name, click the "Resend Invite" button.