This kind of lending applications are treated individually and the reasons for the poor rating can vary. Many people in this situation will want to have a rough idea of their possibilities before embarking on the application process. While a system to assess those possibilities is not generally available, you can improve your chances by fixing any issues with your credit profile if you have time to do so before applying. You can have a confidential discussion with a broker who should be well-positioned to provide an indication of what they could achieve for you.