I see this is your first post so let me welcome you here in the Community. I'll share some information about how you can stop your Accountant from viewing or having access to your QuickBooks Online (QBO).
Follow the steps below on how to stop or remove an accountant user, depending on what Manage Users screen you have. You can verify this by going to the Gear icon then Manage Users and check the address bar of your browser.
If the link ends in usermgt, you have the new Manage Users interface.
If it's legacyusermgt, then you have the old Manage Users interface.
For the new interface, here's how to remove an accountant user:
1. Go back to the Gear icon, then Manage Users. 2. Click the Accountants tab, then locate the name of the accountant you wish to remove. 3. From the Action drop-down choose Delete. 4. Select Delete when the confirmation window will pop up.