For domestic flights within the United Kingdom, such as those operated by British Airways, a passport is not required for travel. However, it is important to note that passengers will need to provide some form of identification when checking in for their flight and boarding the aircraft. Typically, this identification can be in the form of a driver's license, an identity card, or a passport.
While a passport is not necessary, it is advisable to have an official piece of identification to confirm your identity and match the details on your booking. Additionally, children travelling may need to present identification depending on their age and the airline's policies, so it is wise to verify the requirements beforehand.
It is always a good idea to check the specific entry requirements and regulations on the British Airways website or equivalent authorities prior to travel, as policies may evolve or change, and each airline may have specific protocols in place. Safe travels!