An expert on budget travel, author of the TripSchool.ru blog Alexander Andreev, will help you understand this issue.
How visa-free transit works
First of all, the need to obtain a particular visa depends on whether the airport where the transfer takes place has a transit zone where a passenger can stay for some time without going through passport control.
If you are flying, say, to Mexico with a transfer in Paris, you can do without a Schengen visa. You can stay in the international transit zone – accordingly, a visa will not be needed. Upon arrival at the airport where the transfer is planned, you need to follow the signs for Connections, Connecting Flight, Transfer Connections, Transit, Transit Passengers, or Flight Connections, and if in any doubt, find an airport employee and, saying the magic word "Transit," follow their further instructions.
During transit, there are a number of restrictions, individual for each specific country and common to all European Union countries.
For example, consider Germany. In this country, international transit zones are not available in all airports. Moreover, each of them has its own restrictions on the duration of stay.
For example, at the airports of Hamburg and Cologne/Bonn, transit is possible strictly from 4:30 to 23:00. In Berlin – from 06:00 to 23:00 only at Berlin Tegel Airport and only for Air Berlin passengers, and the time between connecting flights must be at least 75 minutes. A similar system operates at Düsseldorf Airport, where visa-free transit is possible from 6:00 to 21:00 and is also organized by carriers only upon request.
Night visa-free transit in Germany is possible only at Frankfurt am Main and Munich airports. The duration of stay at these airports is limited to 24 hours.
At other airports, the international transit zone closes, so if your plane arrives at night, you cannot do without a Schengen visa: without permission to enter the EU, you simply will not be allowed on the flight.
A similar situation exists at airports in France – however, here round-the-clock transfer without a visa is possible at three major airports: Paris Charles de Gaulle, Toulouse, and Nice (except for transit between Terminals 1 and 2). At Paris Orly, you can stay without a Schengen visa strictly from 6:00 to 23:30, and transfers between the South and West terminals are not possible. The same in Lyon: you cannot make a connection between Terminals 1, 2, and 3. In addition, the maximum transit time must not exceed three hours.
These are specific restrictions, but there are also general ones. For example, visa-free transit is not possible if you need to collect your luggage and check it in again (for instance, if the flight is operated by two different airlines).
Transfers in London are a separate matter. For connections within the same airport, roughly the same rules apply as in the rest of Europe. Transfer without a visa is possible, but you must leave the country no later than 23:59 on the day of arrival. Moreover, in the British capital, transit is possible even if your flights are from different airports (e.g., Heathrow and Gatwick). In this case, the final decision on the possibility of visa-free transfer is at the discretion of the immigration officer. In general, the rule most often applies that when flying to America or Australia, arranging a connection with two airports but without a UK visa is possible, but when flying to Berlin or Vienna, difficulties may arise. Another plus for such a transfer is having tickets for a bus to the neighboring airport or confirmation of transfer booking.
You cannot make a transfer in the EU without a visa if you are traveling through two or more airports in Schengen countries. In this case, one of the flights will be a domestic flight, for which you will have to go through passport control, and accordingly, have a Schengen visa. Such transit is not possible if you have a ticket with an open date of departure or the connection time exceeds 24 hours.
Where to find out all this
The easiest way is from a representative of the airline you are going to fly with. Alternatively, upon arrival at the transfer airport.
If you know English, searching for the necessary information is a bit easier: all information about visa-free transfers is available in the Timatic system, which is used by all airlines, airports, and agents. You can use the database, for example, on the Emirates airline website.
To find out about the possibility of a visa-free transfer, provide data on citizenship, final destination, and the country where you plan to transit. Look for results in the TWOV – Transit Without Visa section.
What to consider
There is another potential problem that you may encounter when transferring in Europe, concerning travel to EU countries that are not parties to the Schengen Agreement. For example, when flying to Cyprus, Bulgaria, Romania, or Croatia with a transfer through other EU countries, you will most likely find that the second flight departs not from the international terminal but from one serving flights within Europe. Thus, to move between terminals, you will still need a visa. Before purchasing tickets to these countries, be sure to check with the airlines whether transit without a Schengen visa is possible.
In some extremely rare cases, airline representatives can provide a personal transfer between terminals across the airfield. For example, once when flying to London with a transfer in Copenhagen, upon exiting the plane, instead of the usual Transit sign, I found passport control at the entrance to the Schengen zone.
I did not have a Schengen visa, but after I explained the situation to the border guards, they drove me across the airfield directly to the boarding gate for my flight. I had my boarding pass in hand and did not need to collect luggage. That is why such a maneuver was possible with the help of airline representatives together with security and border control. However, this happens extremely rarely, and hoping that they will accommodate you is at least presumptuous.
Based on materials from Lenta.ru