Applying Overpayments/Duplicate Payments to Client without Applying to Invoice

How do you apply overpayment funds/duplicate payments to a client's matter if there is no invoice to apply it to?  We receive ACH payments for client invoices directly to our operating account.   Legal accounting software programs normally have a "prepaid" account for when a client overpays or duplicate pays an invoice, we are able to post it was account under their matter which links the funds to them so then I am able to transfer the funds (which are unearned) to their trust account.  According to the Florida Bar regulations, ALL unearned funds should be transferred to the trust account and refunded from the trust account.  How do I do this in accounting seed?