There are two ways to fly with a layover, and the legal difference is huge:
1. Through-Ticket (Single Booking): If you booked London to New York via Paris in one go, the airline is responsible. If the first flight is late, they must rebook you on the next available flight for free and provide food/hotel.
2. Self-Transfer (Separate Tickets): If you bought two separate tickets to save money, the second airline doesn’t care if the first one was late. You have “No-Showed.”
Smart Move: Use tools like FlyNRun (powered by Kiwi) that offer “Guarantee” services for self-transfer flights. This gives you the price of separate tickets with the protection of a through-ticket.