Hello there, Louis.

You can permanently delete a client in QuickBooks Online. Here's how you can do it:

1. From the Client's list's Name column open the client's name link.
2. From the Edit client drop-down menu, select Delete permanently.
3. Select Yes, when the confirmation prompt appears.

Also, you can visit this article to know more on how to change a client’s status in QuickBooks Online Accountant: https://community.intuit.com/articles/1771875.

I'll be around if you have any questions about QuickBooks. Have a good one!