Suppose your attorney-client fee agreement requires a client to maintain a certain minimum balance in trust. Click on "Clients" tab, select the client and then click on "Client Details/Edit" tab on the right.  Enter the "Min. Trust Balance" amount and save.  In "Settings/Tools/Reports" -> Edit Business Info option, if "Show Trust Funds On Invoice" option is selected, client invoices will include a sum added to the total to bring the trust account deposit to the min. required.