The manifest helps cabin crew greatly in other things. In case cabin crew are not sure if a passenger sitting in business class is actually a business class passenger, they would check the manifest to see, it's less hassle than asking for the boarding as some passengers might see that as an insult.

Airlines are legally required to maintain an accurate Flight Manifest for every departure for three primary reasons: safety, security, and international law. Firstly, the manifest is a critical accountability tool in the event of an aviation disaster; it ensures that the airline and emergency services have a definitive list of every soul on board (including "lap infants" and crew) for identification and notification purposes. Secondly, for international flights, the manifest is shared with customs and border protection agencies via the Advance Passenger Information System (APIS) to vet passengers against "no-fly" lists and security databases before the plane enters a country’s airspace. Finally, the manifest is used for weight and balance calculations; the ground crew and pilots use the passenger count and seat distribution to ensure the aircraft is properly balanced for a safe takeoff. While much of this is digital in 2026, a physical copy is often printed and kept by the gate agent or the "loadmaster" until the flight is safely in the air to ensure there is a backup in case of a system failure or a mid-flight emergency.