File upload is done after payment is completed. At this point, you will have the opportunity to change the uploaded file as many times as required until final application form confirmation is given. Once this is done, however, it will be impossible for you to change the uploaded file. If a mistake has been made at this stage, please contact our customer support team immediately. There may still be a opportunity to update your file. However, no guarantees can be made. As such, please make sure that the file on our servers at the time of final confirmation is the correct one.