This is for you if you want to leave the UK and you are a national of any other country. It is only valid for one journey. The one-way document, allows travel for one journey out of the United Kingdom only. It cannot be used to return to the United Kingdom. If you are currently in the United Kingdom and are a national of any other country, you may apply for a one-way document. Children cannot be named on the travel document of their parent or guardian. They must apply for their own document.