Round trip vs two one-way tickets?
Is there any substantial disadvantage to booking two one-way tickets, versus a round trip ticket?
Booking vacation travel with family of four for winter, from Northeast US to Mexico. Round trip is pricy and no preferred travel times. Two one ways is slightly cheaper with much preferred timing.
Different airlines there and back, both reputable national US carriers.
Leaving aside the question of round trip versus one-way fares, there are some potential disadvantages to booking your outbound and return flights on separate one-way tickets as opposed to a single round-trip (aka return) ticket— unless all tickets happen to be fully flexible, fully refundable, full-fare tickets, which you won't be buying if you care at all about price.
Using separate tickets for each leg is not unlike booking connections on different tickets— you assume all risk if there is a problem with one leg that prevents you from boarding the next. If you find you need to fly into and out of PBI instead of MIA, you face two change fees instead of just one. If your outbound to OXR is canceled and you get rebooked to LAX for free, you'd need to change your return in a separate call and pay a change fee with the second airline.
Furthermore, if your first flights gets canceled or you get bumped and they can't reschedule you until after your trip becomes pointless, you won't be able to claim a trip-in-vain refund. And while you might be able to find a sympathetic agent for adjusting two separate one-ways on the same airline, it would be most extraordinary to find an agent sympathetic to changes made by another airline. (Of course, the longer the time between your flights, the less the above is a serious concern.)
Secondarily, you may lose some advantages built into round trips, though this is largely dependent on the particular fare rules of the tickets you do buy. For example, a round trip award ticket on United Airlines allows a stopover or an open jaw in each direction, but no stopovers are allowed on one-way tickets, severely reducing the benefit for travelers like me. Additionally, some coupons and other promotions may require a round trip fare.
I would also assume that buying 2 one-way tickets instead of a round-trip ticket would significantly increase your chances of being dragged into an interrogation room.
@pacoverflow: That was chilling to read, thanks for the link. Hopefully combining one-way flights is more common now than in 2013?
I've bought separate Canada/US tickets multiple times, several times one way on Air Canada and the other on United. and once one-way on United and the other on WestJet, and I never had a whiff of a problem with US Customs. Having evidence of the return trip with you is never a bad idea, but no one even broached the question with me.