Issues with booking 2x round-trip tickets (with a 'fake' layover) instead of a multi-city ticket?

Question

We're planning a short multi-city trip within Europe next month. Here's the basic trip, with a few days spent in Prague and Zurich:

WARSAW, PL --> PRAGUE, CZ --> ZURICH, CH --> WARSAW, PL

Searching for multi-city flights, or even one-way flights, comes back with extra hops, and the tickets end up being ~25-30% more expensive. I noticed, however, that if I just booked 2 round-trip tickets (Warsaw-->Prague and Warsaw-->Zurich), then I can get direct flights (except for the Prague-->Warsaw-->Zurich flights) for substantially less money.

My concern is with the return flight from Prague into the departing flight for Zurich. I'd like to plan it so that we'd have a, relatively, short "layover" in Warsaw. But since these are separate bookings, I'd like to know what the potential issues are, or if this can be accommodated easily... To complicate matters, they would be through separate airlines most likely (Czech and Swiss).

• Can we check-in for the Warsaw flight in Prague, or do we have to do it in Warsaw?
• Would we have to go through customs again in Warsaw and back through security? This is part of a larger trip to Poland. We are actually Canadian/US citizens.
• If we have any checked luggage, then I'm assuming we would have to pick them up in Warsaw and send them back through for the next flight. But, if we can somehow avoid having to go through customs again if we don't have checked luggage, would this force us to have to?
• Since these are separate bookings, I'm guessing that one of the major concerns would be that if the first flight is cancelled/delayed, I am completely on the hook for the second one in Warsaw.
• If this is at all a common thing, what would be a recommended amount of time to leave for a layover? I was initially thinking something short, but then some of these concerns started popping up.

Answer 1

1. I would keep trying on the multi-city tickets. You may also get a good fare by adding these onto your transatlantic trip, or combining an open-jaw transatlantic ticket with a single one-way. (I am basing this on your citizenship.) I once booked SFO-PRG-ZRH-SFO for $1 (plus tax and landing fees) more than (SFO-PRG)+(ZRH-SFO), and I recall the PRG-ZRH link separately was hundreds of dollars.
2. Poland, Czech Rep, and Switzerland are all in the Schengen zone. You will clear immigration once, in the first country you arrive in. For immigration purposes, these flights are domestic. [Exception: some of the super-cheapo airlines, e.g., Ryanair, require non-EU citizens to visit a special Visa Desk before each leg. Skeptics think this is to charge for missed flights and connection.] Your problem with checked luggage is not customs (which will be the red lane/green lane system), but that it is very unlikely that different airlines will be able to through-check your bags. The problem with reclaiming them is not customs, but you will be leaving the secure zone and have to queue up again for security.

Your plan is possible but risky. I would allow at least 4 hours in Warsaw, because if you misconnect, you are correct, you are on the hook for everything.

Answer 2

Nesting tickets like this is common, or at least it is common for people who do these kind of trips regularly. It is perfectly allowed but it comes with inconveniences and risks, part of the reason why it is cheaper. It is also quite often the only way to construct the itinerary that one desires between non-cooperative carriers.

If you are carry-on baggage only, you can likely complete most check ins online and use an app instead of a printed boarding pass. In this case there is no reason to exit the secure departure lounge in the airport. Airside customer service desks can also check you in and print boarding passes, avoiding unnecessary security. (For the super low cost carriers, this does not apply.)

If you are taking bags, expect to have to collect and re-check in. It is narrowly possible a check in agent might be willing to through-check onto a separate ticket on a separate carrier, but travelling on cheap tickets in Europe, it is simply not worth their time.

If you miss a flight, you will probably be treated as a no show and the remainder of your ticket will have zero value. That includes the return portion of the affected ticket. Most airlines will not help you except through selling you a new ticket, although it never hurts to ask.

You will need to consider managing that risk carefully. Walk up prices can be higher than transatlantic flights, particularly if you are on a tight schedule. I advise you to research alternative options in advance so you have a plan B costed and ready to execute (maybe it is “hire a car”, “take the train” or even just “forget the side trip to Zürich”). If you are doing this just hoping it will all be fine and you will definitely be on time to your own wedding in Zürich later the same day, then you are doing this wrong. If you have weighed the options, added some padding between your flights and you don't mind being late, then you will probably be okay.

In general I prefer to get all “connected” flights into one ticket, even at an inflated cost, but then sometimes back-to-back ticketing is an acceptable solution.