Need to knowImportant passport rule for teenagers turning 16 this yearFailing to follow specific renewal guidelines could result in rejected applications or cancelled holidaysBrits over 16 wanting to travel will need a valid adult passport) (Image: Jordan Pettitt/PA Wire)The Passport Office has issued an urgent reminder to parents of teenagers approaching a major milestone. With roughly 800,000 UK teens set to turn 16 in 2026, failing to follow specific renewal guidelines could result in rejected applications or cancelled holidays. Mandatory Status: While a child passport can be used until it expires (even past age 18), any renewal processed once a person has turned 16 must be for an adult document by law. Cost of Application: An adult passport currently costs £94.50 when applying online, while paper applications are more expensive at £107; the digital "PEX" system also allows for instant tracking. No Urgent Service: Critically, the "same-day" fast-track service is not available for those transitioning from a child to an adult passport, meaning these applicants cannot rely on last-minute appointments.