I am trying to add a user. He has opened his invite but is unable to get on. How can I get him access to our account?

Good day, Mike.

I can guide you on reaching out to the Live Expert Support Team.

Here's how:

1. Go to the Help icon.
2. Select Search, then type a keyword into the Search bar. 
3.  Click Contact Us.
4. Choose how could you like to Connect with us, either via Chat or Callback.

Please know the best time hours to reach Live Expert Support Team.

Furthermore, here's an article to help you check and gain more insights on every user in QBO: User roles and access rights in QuickBooks Online and Intuit Enterprise Suite.

Once this concern is solved, you can refer to this article if you need to delete a user from your account: Add, manage, or delete users in QuickBooks Online.

Please hit the Reply button if you have any further questions about managing and inviting users to your QuickBooks Online account.