The UK Immigration Rules were amended in April 2013 to include a new category of leave: ‘Part 14 stateless persons’. Statelessness arises when a person is not a national of a state. The guide focuses upon the definition applied by the UK Immigration Rules: ‘a person who is not considered as a national by any State under the operation of its law’. This definition is taken from the 1954 Convention relating to the Status of Stateless Persons (the 1954 Convention). An important feature of the Immigration Rules relating to stateless persons is the scope they provide to secure recognition by the Home Office of statelessness, a legal condition which itself has important consequences in international law. The guide sets out the view of the authors on best practice in advising and representing clients considering or making an application for statelessness leave in the UK. The UK law in this area is in its infancy and is likely to develop particularly quickly. Some key questions of law and practice have yet to be addressed by the courts; the guide provides a snapshot of the state of play as at September 2016. It is aimed at those who may represent clients considering whether and when to make an application for leave to remain as a stateless person. It may also be of use to organisations working with potentially stateless persons who may refer them to legal advisers. It is a joint publication of the Immigration Law Practitioners' Association and the University of Liverpool. The authors are in-house solicitors in the Law Department's Law Clinic