For domestic flights within the United Kingdom, a 5-year-old child does not officially require a photographic ID, provided they are traveling with an adult who can vouch for their identity. Most major UK carriers, including British Airways, easyJet, and Loganair, state that identification is not mandatory for children under the age of 16 on domestic routes. However, the accompanying adult must present a valid form of photographic identification, such as a passport or a driving license. While not strictly required, many parents choose to carry a copy of the child's birth certificate or their own passport for peace of mind, especially if the child has a different surname. It is important to note that these rules only apply to travel within the UK (England, Scotland, Wales, and Northern Ireland); for any international flight, including those to the Republic of Ireland or the European Union, every passenger regardless of age must have their own valid passport.