Whether a newborn can fly without a passport depends entirely on the destination of the flight. For domestic travel within the same country (e.g., New York to Los Angeles or London to Edinburgh), a newborn does not require a passport. However, most airlines require a copy of the infant's birth certificate or a hospital-issued "record of live birth" to verify their age and identity, especially if they are flying as a "lap child." For any international flight, including those to neighboring countries, a newborn must have a valid passport of their own. There are no "grace periods" for infants in international aviation; even a one-week-old baby must have their own travel document and, in some cases, a visa. Parents should be aware that obtaining a first passport for a newborn can take several weeks or months, requiring a specific photo (which can be challenging with an infant who cannot hold their head up) and the physical presence of both parents or notarized consent. Always check the specific entry requirements of your destination country before booking.