If you do not have a Schengen visa or if your Schengen visa has expired, and your itinerary requires a layover in a Schengen country, you need to pay special attention! If you are transiting through the airport, a Schengen visa is required, either a regular Schengen visa that allows you to stay in Schengen countries or a Schengen transit visa (also known as an A visa) that must be obtained in advance.
If you hold a connecting flight ticket (with only one booking number), your luggage is checked through to the final destination (no need to collect luggage and check in again), and you proceed directly through the airport transit channel, it is equivalent to not entering the Schengen country. In this case, not having a Schengen visa or a Schengen transit visa is acceptable. The following situations are slightly more complex, and you should check if you need to apply for a transit visa or a Schengen visa in advance.
1. Non-connecting flights, luggage cannot be checked through, and you do not leave the airport.
Some travelers do not purchase connecting tickets but rather two one-way tickets, requiring them to collect their luggage and check it in again. In this case, you may be stopped and asked to present a Schengen visa because the luggage collection area is likely outside the airport transit zone. Even if you do not leave the airport, it is equivalent to entering the Schengen country, so it is reasonable for them to request a Schengen visa.
According to the Schengen official website, citizens transiting at an airport in a Schengen country from a non-Schengen country to another non-Schengen country must hold an airport transit visa to pass through the international zone of the airport.
2. Purchasing a connecting flight ticket, not leaving the airport for the layover, but luggage is not checked through.
Even if you have purchased a connecting flight ticket and do not leave the airport, you may still be stopped due to not having a Schengen visa. This can happen due to flight sharing or last-minute changes, where the luggage is not checked through to the final destination. Collecting luggage and checking it in again brings you back to the first situation. Although this situation does not occur frequently, it can still be quite frustrating if it happens.
Note: If your luggage is not checked through during the layover (you need to collect your luggage and check it in again), a Schengen visa is required in this case. Although generally, purchasing connecting tickets should not lead to such issues, it is advisable to confirm in advance to prevent being denied boarding later.
3. Connecting flights with two layovers in Schengen countries.
According to the Schengen Agreement, foreign travelers must complete immigration procedures upon arrival in the first Schengen country, regardless of whether the ticket is a connecting ticket or whether the luggage is checked through to the destination country. After entering, the remaining travel between Schengen countries is similar to domestic inter-provincial travel, with no border control or customs. Therefore, when transiting once in a Schengen country, it may be acceptable to show the next flight ticket, and the staff may allow you to pass. However, if you need to transit twice, and the second layover is also in a Schengen country, there are no customs or border checks between Schengen countries, so a Schengen visa is mandatory for the first layover.