How to Plan a Multi-City Flight Itinerary

Understanding Open-Jaw and Multi-City Structures

A multi-city itinerary is any trip where you fly into one city and out of a different city. The simplest form is an "open-jaw" — flying London to Paris and Paris home to London is a standard round-trip, but flying London to Paris and returning from Rome to London is an open-jaw that lets you travel overland from Paris to Rome without backtracking. Airlines price open-jaws as round-trip equivalents, meaning the fare is typically similar to a standard return but covers a geographically more useful routing.

A true multi-city booking involves more than two flight segments with different departure and arrival cities. Example: New York → London → Paris → Barcelona → New York. Each segment is priced independently but combined into one booking record, allowing a single ticket number, through-checked baggage on connected segments, and single-point disruption protection (if one leg is canceled, the airline must rebook the entire itinerary). This is meaningfully different from booking four separate one-way tickets, which have no relationship to each other and require you to handle disruptions independently on each segment.

ITA Matrix (matrix.itasoftware.com) is the best tool for researching complex multi-city routing before booking. Enter up to 8 city pairs in the "Multi-city" search, set date ranges for flexibility, and ITA Matrix will find the cheapest combination of airlines and fare classes. It shows which airlines offer the lowest fares on each segment and whether interline agreements allow baggage transfers between carriers. ITA Matrix doesn't book directly — use the itinerary details to book on Google Flights, the airline directly, or a full-service travel agent for complex itineraries.

Hub-and-Spoke Exploits: Getting More for Less

Airlines price tickets based on origin-destination pairs using published tariffs. A quirk of this system is that hub-connecting itineraries sometimes cost less than the direct segment because the airline competes more aggressively on long-haul routes than short-haul feeders. Flying from Nashville to Rome by booking Nashville–Rome through Atlanta may cost $650, while booking Nashville–Atlanta and then Atlanta–Rome separately might cost $120 + $700. The combined ticket exploits the airline's published fare for the Atlanta–Rome segment, which is discounted to compete with other transatlantic carriers.

This logic powers what frequent flyers call "positioning flights" for award tickets and cheap international fares. If you live in a secondary market, flying first to a major hub — JFK, LAX, MIA, ORD — on a cheap domestic ticket and then catching an international fare from that hub often provides more options and lower prices than routing directly from your home airport. The downside is risk: if the domestic positioning flight is delayed or canceled, you've missed the international connection and the two tickets have no relationship to each other unless booked as a multi-city itinerary.

Alliance hubs amplify this strategy. If you're flying with Star Alliance carriers, United's hubs (IAD, EWR, ORD, LAX, SFO) connect seamlessly with Lufthansa (FRA, MUC), Swiss (ZRH), and other Star Alliance partners. Booking a through-ticket Washington–Chicago–Frankfurt–Rome through the alliance booking system creates a single itinerary with baggage transfers and disruption protection across all segments, even though multiple airlines operate different legs.

Round-the-World Tickets: When They Make Sense

Round-the-world (RTW) tickets are alliance-issued products allowing travel to multiple continents on a single ticket. Star Alliance's RTW product allows up to 16 segments on member airlines, visiting up to 15 destinations, priced either by mileage band or number of continents visited. Typical prices range from $4,000–$7,000 in economy for a genuinely global itinerary. Oneworld's Explorer product and SkyTeam's RTW product work on similar principles.

RTW tickets make financial sense only for travelers planning to visit 4+ continents over a journey of 3–6 months. A typical RTW route — New York → London → Dubai → Bangkok → Tokyo → Sydney → New York — covering 6 stops would cost $4,500–$6,000 in economy on an RTW ticket. Booking each leg separately as promotional fares (catching sales over the course of the year before departure) might cost $2,500–$4,000 total, but requires more planning, has no single-ticket protection, and doesn't allow the flexibility of RTW's backtracking rules.

The critical rules for RTW tickets: travel must be in one continuous direction (eastbound or westbound — you cannot double back across an ocean), all flights must be ticketed within the alliance (no mixing with non-member carriers), changes after ticketing incur fees ($150–$300 per segment change depending on tier), and the ticket must be completed within one year of first travel. Stopovers of up to 1 year are permitted in cities along the route, making RTW tickets the framework for long-term world travel rather than vacations.

Practical Booking Strategies for Complex Itineraries

For itineraries involving 2–4 cities on major carriers within an alliance, booking directly through the airline's multi-city tool is the simplest approach. United's "Multi-city" search at united.com, Delta's comparable tool, and American's AAdvantage booking platform all allow 4–5 segments with through-baggage checking on connecting itineraries. The interface is less flexible than ITA Matrix for comparison shopping but produces a single valid ticket number.

For complex itineraries involving budget carriers, non-alliance partners, or unusual routings, a consolidator ticket agent — companies like Vayama, CheapOair, or Priceline's bulk-ticket desk — sometimes has access to published fares and combinations not available through consumer booking tools. These agents work with airline consolidator contracts that provide net fares below published retail prices, particularly on international long-haul routes. The trade-off is limited flexibility: consolidator fares are often highly restricted and customer service response is slower than booking directly.

When mixing airlines — booking Delta for the outbound and Lufthansa for the return on the same itinerary — the safest approach is booking each separately but building in enough connection time that a delay on one segment doesn't strand you. Airlines have no legal obligation to protect you on a missed connection to a separately ticketed flight on a different carrier. A minimum of 3 hours between a domestic arrival and an international departure when the tickets are separate; 4 hours in airports known for congestion (Heathrow, JFK, Chicago O'Hare).

Overland Segments and Open-Jaw Optimization

Building overland segments into an international itinerary is frequently the best way to see more of a region while reducing total air cost. Flying into Rome and out of Barcelona — spending a week traveling through southern France by train — costs no more than a standard Rome–Barcelona airfare would add to the itinerary, because the airline prices the two city pairs independently. The open-jaw fare for New York–Rome (inbound) and Barcelona–New York (outbound) is often within $50 of a standard round-trip to Rome, despite covering a geographically broader journey.

Europe's high-speed rail network makes overland segments particularly practical. The TGV covers Paris–Barcelona in 6.5 hours; Eurostar connects London and Paris in 2.5 hours; the Frecciarossa connects Rome and Milan in 3 hours. For segments under 800km in Europe, train travel is often faster city-center to city-center than flying when airport transfer time is included, and the train fare is typically €30–€80 — far cheaper than a short-haul flight when checked bag fees are included.

In Southeast Asia, the "open-jaw" principle works across budget carriers. Flying into Bangkok and out of Singapore — with overland travel through Malaysia by train or bus — is a common backpacker itinerary that can be structured as an open-jaw on a single alliance ticket or as two separate budget carrier bookings. AirAsia, Scoot, and VietJet cover intra-Asian routes cheaply enough that connecting flights within a single country (Bangkok–Chiang Mai, for example) are often cheaper to book separately rather than as connecting itinerary segments.