Hello there, @cabocraft.

I see the importance of adding a user that can only manage invoices but can't edit or delete customers in QuickBooks Online.

In QuickBooks, you can add different types of users. You have the option to add someone with limited access to the account. If they have access to customers and vendors, they can enter quotes, invoices, sales receipts, credit notes, refunds, charges, and credits. However, they can add, edit, and delete customers, suppliers, products, and services.

Since this feature is not available in QuickBooks Online, I suggest sending us a feature request.

Here's how:

1. Click the Gear icon, then select the Feedback button.
2. Type in your comments or product suggestions.
3. Hit Next.

Our Product Development team will use your insightful feedback to enhance your QBO experience. The webpage for QuickBooks Online Feature Requests allows you to follow feature requests.

Refer to user roles and access rights to QuickBooks Online account and learn more about their limits.

Let me know if you have additional questions about user types in QuickBooks Online. I'm always here to help.