Travel-On doesn’t offer Basic Economy fares on American, Delta, and United, but you do sell similar Frontier fares. Why?

It has to do with the identity of the airline and the way the fares are filed. Delta, American, and United are not “low cost” carriers. They offer both regular economy and basic economy on the same routes and file their basic economy fares in such a way that they can be easily excluded from the search for corporate travelers. Frontier is a low cost carrier – their fares never include seats, carry-ons, etc. Their base fares are typically lower so sometimes adding the basics such as seats and bags is still very economical. That’s not generally true of Delta, American, and United. Note that Frontier does offer a package called “The Works” that can be purchased along with the ticket that includes one carry-on, one checked bag, and a seat assignment. When booking Frontier on Deem or Concur there is a message on the screen that outlines the differences. When booked with an agent he or she will outline the differences.