Hello flemingpeggy,
When you invite a user to the company file, they'll need to accept the email invitation using their Intuit login crendentials. If they haven't received the email invitation, you can ask them to check their junk email or spam folders.
You can also resend the invitation email. Feel free to browse this article for more information: Why Did My Invited Users Not Receive Their Email Invitations for QuickBooks Online?.
Let me know how this goes so I can help you more. Additional details would be much appreciated. Thanks in advance!
