How can I disable Invoices?

I know its possible to disable quotes, or remove them from the menu so that they can use everything else but invoices, we only need quotes.

There is no proper and easy way to remove a module, not even quotes.
Removing it from the menu would be one of the first steps to do.

Yea Can I just remove it from the Top and side menu? I don’t mind if its still their in the back end and in code, I just want to minimize user’s clicking in the wrong area’s right now. Perhaps later I can turn it back on and start using it.

Yes you are right.

What about using IIS Request Filtering to deny /invoices URL.

IIS Request Filter

IIS Deny Page if someone click invoices.