Is it cheaper to book separate one-way tickets?

Rarely. While it might look cheaper initially, you lose the protection of a single ticket. If a flight is delayed, the airline has no obligation to rebook your next leg if it was booked separately.

What happens if I skip one flight in my multi-city itinerary?

Most airlines will automatically cancel every subsequent flight in your booking. Never skip a leg in a multi-city sequence.

How to Book Multi-City Flights for Complex Itineraries

Use the 'Multi-City' search tool on flight aggregators like Google Flights or ITA Matrix instead of booking separate one-way tickets. This ensures you are protected under a single booking reference, which simplifies cancellations and prevents you from being stranded if a connection is missed.

Map your route first. Write down your segments in order. Use a spreadsheet to track dates and airports. If you are crossing oceans, prioritize booking the long-haul legs first as they have the least frequency.
Use the Multi-City search tool. Do not search for separate one-way tickets unless you have no other choice. Navigate to Google Flights, click the dropdown menu that defaults to 'Round trip,' and select 'Multi-city.' Add each leg of your journey one by one.
Check the connection protection. If a multi-city search returns a ticket where the carrier changes (e.g., Star Alliance to SkyTeam), verify if it is on a single 'interline' ticket. If the site warns you that it's a 'self-transfer' or 'separate tickets,' the airline is not responsible for your next flight if the first one is delayed.
Leverage ITA Matrix for complexity. If your route is highly technical (e.g., open-jaw flights or stopovers), use Google's ITA Matrix. It allows for advanced routing codes and multi-city parameters that commercial booking sites often struggle to display.

Is it cheaper to book separate one-way tickets?: Rarely. While it might look cheaper initially, you lose the protection of a single ticket. If a flight is delayed, the airline has no obligation to rebook your next leg if it was booked separately.
What happens if I skip one flight in my multi-city itinerary?: Most airlines will automatically cancel every subsequent flight in your booking. Never skip a leg in a multi-city sequence.