It’s no secret that some airlines have little love for online travel-booking sites. Southwest only lets travelers book fares directly through the airline and Delta has cut ties with a number of booking/listing sites, including TripAdvisor. The airline industry claims that booking directly will get consumers the lowest prices on airfare, but is that true?

A rep for Airlines for America, the trade group representing the nation’s largest carriers, recently told the Washington Post’s Wonkblog that, “Airlines want to sell tickets, and they want to do so in the least costly way possible, which is why buying tickets directly from an airline website provides the lowest fare.”

To put that to the test, we selected a trio of routes around the country and compared the fares listed on each of the airlines’ sites with what came up on booking/comparison sites Priceline.com, Kayak, and TripAdvisor.

First we looked at booking tickets from Philadelphia to Atlanta. All of the booking sites had the same range of results, showing the lowest-priced tickets on the major carriers going from $175 to $543, with American Airlines having the cheapest of those fares.

These numbers were identical to what we found on each of the sites for the individual airlines, so in this case there was no savings advantage in booking directly through the carrier.

The same was true when we searched for fares from Chicago to Miami. Both the travel aggregating sites and each of the airline sites listed tickets with starting prices of $249 to $520. Once again, AA had the cheapest seats available of all the majors.

The third time was the charm though, when we looked for tickets from NYC (all airports) to San Francisco. Kayak, et al, matched the airline sites’ rates for Delta and United, but the price listed on AA.com was $571, which is $25 less expensive than the price given on the booking sites.

And how does Southwest compare? We looked at prices for each of these itineraries on Southwest.com, and the airline’s competitiveness varies wildly, from being near the low end of the range for the PHL-ATL trip ($188) to the high end of the range for NYC-SFO ($731). The Chicago-Miami trip was reasonably competitive at $291, but requires you to fly to Ft. Lauderdale (which may be better for you, depending on where you’re going).

This is by no means comprehensive, but it does show that you can get less-expensive tickets by booking directly through an airline’s website and that Southwest’s limited booking options doesn’t mean it’s always cheaper.

Because the booking sites allow you to do an immediate comparison of options, they make a great starting point. Once you’ve got the array of prices available to you, then you can double-check a price or two against the individual airline sites.

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