On a single ticket, the airline rebooks you on the next available flight at no charge, and may owe meals or a hotel if the delay was its fault. On separate tickets you're on your own — you'll buy a new ticket.
One ticket (protected connection): the airline is responsible. Go to the transfer desk or use the app; many airlines rebook automatically. If the cause was within their control (crew, maintenance, late inbound) you’re usually entitled to meals and, overnight, a hotel. In the EU/UK, EU261/UK261 compensation may apply for long delays.
Weather or ATC: rebooking still happens, but compensation and hotels are often not owed.
Separate tickets: the second airline treats you as a no-show. Some will rebook for a fee; most require a new fare. This is why self-connections need three hours or more and travel insurance.
Tips: know your rights before you fly, screenshot the delay, and ask for the rebooking in writing.
Related questions
What is a layover, and how is it different from a stopover?
A layover is the time between connecting flights on one ticket — usually under 24 hours. A stopover is a deliberate stay of more than 24 hours (often days) at the connecting city, sometimes offered free by hub airlines. Full answer →
My flight was cancelled — what are my rights?
Everywhere: a refund or rebooking, your choice. In the EU/UK: also meals, hotel if overnight, and up to €600 compensation unless the cause was extraordinary. In the US: a cash refund is required for cancellations; compensation is not, though some airlines offer it voluntarily. Full answer →
Airline, airport and government rules change without notice. Treat this as a starting point and confirm with the airline or authority for your specific trip. Request a correction if something is out of date.