It would be nice to be able to put customers on account hold. That way, the technicians can refer them to accounting before they help them.
You can edit a customer and enable “Enable Internal Ticket Warning”. On the customer screen, there’s a spot called “>_SCRIPTING” and you can toggle that to Disabled. You can also create a new Custom Customer Field of type Popup. If I recall, this pops up once per session when you go to the customer. The Internal Ticket Warning will come up any time someone attempts to create a ticket.