Want a quick 30% discount on your family’s trip to Australia, Europe or Hawaii? In the crazy airfare world, sometimes buying two tickets is cheaper than one.

Pairing two discounted tickets together to create your own connecting itinerary can often be less expensive than flying on one ticket, if you take advantage of airlines’ city-specific specials, or create your own route using discount airlines.

The strategy comes with serious trade-offs. You may have to recheck bags or stay overnight in a connecting city. And if you’re late for your connecting flight, your trip could be canceled as a no-show.

But mileage junkies who take advantage of ticketing quirks have been using this strategy for years. For travelers dealing with some of the highest fares in years to Europe, Asia, Hawaii and other long-haul destinations, doing it right can save hundreds of dollars a ticket.

“You have to put your cheapskate hat on,” said Tom Parsons, chief executive of, a discount travel site. “You just have to check the gateway cities and do the math.”

Carriers routinely offer special deals in particular cities. But they don’t let reservation systems and online ticket sellers to combine those ultracheap fares with connecting flights in a single transaction. Allowing this could cause a widespread fare sale that would trigger price matching and even more fare cutting by competitors. But travelers can build their own itineraries by buying two separate tickets—with the same airline or different ones—and creating their own connection.

When Air Berlin, which begins flying from Chicago in March, posts cheap prices to German cities, other carriers match fares on flights from Chicago. Since the low Chicago fares can’t be combined with other cities on the same ticket, people outside the Windy City can find separately a cheap ticket to Chicago and build their own connection to save big bucks.

For example: A Dallas-Düsseldorf round trip in late May costs $1,337 when priced as one ticket on United Airlines. Use a $677 round-trip ticket between Chicago and Düsseldorf with a $243 Dallas-Chicago round-trip—both on United—and you can save $417 per ticket, or 31%.

Turkish Airlines, trying to expand more in the U.S., has driven prices as low as $409 round-trip between Washington, D.C., and Istanbul, including all taxes, fees and fuel surcharges. Other airlines have matched on some flights. Washington also is home to some cheap flights to Athens. So if you can find a cheap ticket to Washington, you’ve got a great deal to Europe. Likewise, a trip to Rome from Atlanta can be $750 cheaper if you buy a ticket to New York and then a New York-Rome round-trip.

In some cases, the two-ticket trip puts you on the same airplanes that you would have booked with a one-ticket itinerary. United, for example, has prices as low as $614 from Houston to Istanbul in April and May. A traveler in Austin, Texas, could buy that, along with a separate $125 round-trip on United between Austin and Houston, and avoid United’s $1,137 Austin-Istanbul round-trip—on the same airplanes. Savings: about 35% off the one-ticket price.

You can also build an itinerary using discount airlines that don’t link their fares with other airlines. Hawaiian Airlines was running a recent sale from West Coast cities to various Hawaiian destinations. Pair those tickets with flights on Southwest Airlines, for example, and beat the one-ticket price of major airlines. Those kind of deals don’t show up in airline or travel agent computers or online searches because Southwest doesn’t “interline,” or share routings with other carriers.

In general, most big international gateways offer the opportunity for double-ticket savings on select routes. It helps that domestic discount airlines have increased their service to international hubs, including New York’s Kennedy International Airport, San Francisco, Los Angeles, Chicago, Atlanta, Dallas, Houston, Philadelphia and Washington.

Rick Seaney, co-founder of, says he uses the two-ticket trick frequently for trips to Asia. From his home in Dallas, Mr. Seaney finds the cheapest flight to his destination from a West Coast city, then a cheap ticket from Dallas to that West Coast gateway. He spends the night on the West Coast and still saves hundreds of dollars.

“The savings can be half the price,” he said. Mr. Seaney calls the trick “virtual interlining”—building connections airlines don’t want constructed.

The tactic can work best in summer when discount airfares are harder to find. For a June 11 to 18, the lowest round-trip airfare from Atlanta to Berlin was priced on Friday at $1,541. The New York to Berlin fare was $680. With discount competition between New York and Atlanta, the lowest round-trip are to JFK was $258. That is a savings of 39%.

Airlines say buying two tickets doesn’t break their rules. Carriers discourage the practice, but say it isn’t a serious threat to their pricing strategies because most fliers won’t go to the trouble. “If you see it and you can book it, you can take it,” said US Airways spokesman John McDonald.

The hassles can be significant. When flying on two tickets you’ll likely have to claim and recheck your bags—potentially costing two baggage fees, as well as the time you’ll have to plan between flights and the hassle of leaving and re-entering secure areas.

“If you’re a light packer, this is the best way to travel,” Mr. Seaney said.

Make sure to leave plenty of time for connections. If one airline runs late, you could end up being a no-show for your second ticket, and that could cost you dearly to get rebooked. Consider arriving in your gateway city a day ahead of time and staying overnight. The hotel cost erodes some of your savings, but it does give you a chance to spend some time in another city. Watch out for trips that use different airports in the same city—that can add cost and require extra time for a bus, train or cab between airports.

Using discount airlines in Europe can also add to savings after you land. Europe has extensive discount airline service on Ryanair, easyJet and other carriers. But beware: The discount carriers often use out-of-the-way air fields and you can find yourself with long transfers between airports.

And watch out for hefty baggage fees on European discounters. Checking a single 40-pound bag for a trans-Atlantic flight would be within the free allowance of most airlines, but if you also have a 40-pound carry-on bag, you’ll pay $288 for excess weight on easyJet, plus a $40 baggage fee when checking in at the airport.