Users should be able to recall invoice requests that are In Process. A user might need to make a change to or delete an invoice request for what ever reason and such a change should not require that the contact an approver up the chain of command have the request rejected. Or an approver might approve an invoice in error or later recognize that a change is needed, and they should be able to ask the user to recall the request rather than again needing to contact an approver up the chain of command to have the request rejected.