I'm having a senior moment, as this hasn't happened in ages. Can we charge a consumer mortgage applicant (who provided intent to proceed) an underwriting fee and other hard costs (appraisal, title insurance cancel fee, flood determination) when the loan request was approved but not accepted?

You can charge them but whether you can collect them depends if you actually contracted for them and how far you are willing to go if they do not pay.

Thanks Dan! Agree, we might not end up collecting, but good to know it's permissible to ask for reimbursement. (We actually did get the appraisal deposit, but there were more costs as this went almost to closing before the borrower withdrew.)