Can we order an appraisal for a loan before we have an application?

Scenario:
Customer currently has a jumbo loan with us, they wish to refinance at a lower amount to get out of the jumbo category. In order to know how much the customer needs to pay down the current loan we need to order an appraisal. The customer would pay for the appraisal but does not want to "officially" apply until they fully understand what needs to be done (financially).