Visa Extension Application Review Service
Department of Homeland Security, USCIS, “suggest you file at least 45 days before your stay expires or as soon as you determine your need to change or extend status.” Furthermore, please note that gathering required docs and completing required forms can take several weeks. Therefore, you should start preparing as soon as you have decided to change or extend status.
All documents and forms must have the pdf file extensions to be uploaded. For letters, it can have pdf, rtf, doc, or docx extensions. To upload multiple documents and forms, press and hold the Ctrl key for Windows or the Command key for Mac.