You generally need to apply for and obtain a travel document before you leave the United States. Before planning travel, please consider USCIS processing times.How to apply for a document to travel outside the UK if you're not British and you cannot use or get your own national passport. Is it worth submitting extra documents eg. You must have a valid travel permit to leave the U.S. while your green card application is pending. You are now ready to use the cbp1 mobile application to request Advanced Travel authorization using the cbp1 mobile application. In this post, we will walk you through the various ways you can check your UK visa application status, so that you can stay informed and uptodate.