Emergency Travel Documents Service - Service Assessment
An emergency travel document (ETD) enables you to get back to the UK or your country of residence from wherever you are if your passport is not available for one reason or another. It is only usable for a defined journey which is written into the document: when you get back, the document is withheld by Border Force and later destroyed by the Passport Office (HMPO). It is more expensive than a passport and so is usually for emergencies. The service has a very wide user base.