You need a passport to travel and will be prevented from boarding your flight if you do not have one. Some countries will require you to have a valid passport for 6 months after your return date. This does vary from country to country, and we recommend that you check the Foreign and Commonwealth Office (FCO) website for advice for the specific country you are travelling to. If you need to organise a new passport, please allow plenty of processing time before your departure, although you can pay an additional fee to via the Post Office Passport Check & Send Service to expedite UK passport delivery. More information can be obtained via the following website https://www.gov.uk/browse/abroad/passports