Yes, travelers are generally required to present a valid passport when flying with Jet2. This requirement is particularly important for international flights, as a passport serves as a primary form of identification and is necessary for border control. For domestic flights within the United Kingdom, a passport is not mandatory, but travelers are still encouraged to bring another form of identification, such as a driver's license or national ID card, as airlines may request identification for check-in and security purposes. Travelers should also ensure that their passport is valid for the entire duration of their trip, as some countries have specific entry requirements regarding passport validity. It is advisable for passengers to view the latest travel guidelines and requirements on the current Jet2 website to stay informed about documentation needed for their journey.