09/30/2012 10:04 am ET Updated Nov 30, 2012

Booking Code-Share Flights: Ask Airfarewatchdog

Have a question about travel or airfares? We answer as many as we can, either by email to or in our Q&A column. You can also post your question in the comments below.

Booking Direct Vs. Online Travel Agency?

Q: I read recently that you can save money by booking online directly with the airlines rather than on a site like Expedia, even though the contracts between the airlines and the online travel agencies prohibit the airlines from offering lower rates. Allegedly the airlines circumvent this restriction by offering discount codes in emails to their frequent fliers or through Facebook and Twitter or through email. I don't mind going directly online to the airline's web site but is there a way for the rest of us who are not frequent fliers to find discount codes?

A: You're correct that airlines are using promo codes to entice passengers to book directly on their sites. We see frequent 10%- to even 50%-off promotions. Airlines hate paying fees to computerized reservation systems or to travel agents, whether online or "bricks and mortar." In fact, it's one of their largest expenses, after fuel, airplane purchases and labor costs. The beauty of using an online travel agency is that you can easily compare prices, and you'll learn if it's cheaper to fly out on one airline and back on another, something that an airline website won't tell you. Price aside, you can also find a range of convenient flight times among several carriers at a glance. To learn about promo codes, sign up for your favorite airlines' emails. The Airfarewatchdog Blog also lists all airline promo codes.

Code Shared Flights

Q: When booking international flights online, I increasingly find that the airline selling the fare isn't the airline actually flying the route. For example, I'll search for a flight on and see that the lowest fare is sold by Lufthansa but the flight is flown by United. Sometimes we don't even learn this until we get our confirmation, or the flight is sold by Delta but we'll be flying on Alitalia. How can we avoid this situation and why do airlines do this in the first place?

A: This is called code sharing, and it's a way for airlines to share capacity, appear to have larger route networks than they actually do and increase profits. It can be quite annoying if you have a strong preference for one airline over another. Often, when looking online at Orbitz or other fare comparison websites, you'll see that two different airlines fly the exact same route at the exact same times but at very different prices. That's your first clue that this is a code share flight. If you're unsure what you're buying, it's best to call the online travel agency in such cases to ask exactly which airline's "metal" you'll be flying on. To its credit, code sharing can often be a way to save significantly if one airline is selling the flight for considerably less than its code share partner.