NOTE: Each individual seeking to travel and return to the United States must file their own Form. All applications must include your current passport with at least one blank visa page on both sides.FCDO travel advice for USA. Includes safety and security, insurance, entry requirements and legal differences. Permanent residents use Form I-131A to obtain travel authorization after losing a green card or reentry permit while traveling outside the United States. If you are travelling to and from London, you'll need to show a valid travel document, along with your ticket. A valid green card (or equivalent valid proof of status in the United States). Who is required to have a travel authorization? To apply for a new travel document, you must go to the embassy or consulate in person so that your identity can be checked. The same applies to your children.