Sterile transit is a term for a situation in international travel where one can enter and leave (transit) part of a country's territory without technically (legally) entering the country itself, hence without customs or immigration formalities.
This most often applies to international flights. For example, consider flying from country A, changing planes in country B, then flying on to country C. If sterile transit is allowed, then travellers do not need to go through country B's customs or immigration checks. However, they must remain in a restricted zone on the air side of the airport, and in most places they and their hand luggage will still go through security screening.
Sometimes other modes of transport may be involved. For example, you can land at Hong Kong airport and take a ferry to either Macau or mainland China without going through procedures to enter Hong Kong. See Hong Kong Airport for details.
Some countries, notably the USA, do not allow sterile transit at all. Canada generally does not allow it, though there are a few limited exceptions for people flying between Asia and the US. Most other countries allow it, but it may only be available at specific airports and sometimes not for all passports or all for combinations of flights.
In some cases, you may need a transit visa even if you aren't required to pass through customs and immigration.
Understand
[edit]- See also: Border crossing, Planning your flight, Arriving by plane
Sterile transit is almost always more convenient for the traveller, since it avoids formalities that are often time-consuming and usually quite boring. Sometimes it also saves money, as it may avoid the need to pay for a visa. In other cases it significantly reduces risk; if you do not technically enter the country, then you are not subject to refusal of a visa, or arrest or deportation. It also saves work for border officials, and it may even benefit other passengers by making the queues for customs and immigration shorter. However, some countries may require you to have a visa even if you do not intend to pass through customs and immigration.
For example, consider a flight from Southeast Asia to Canada with a change of planes at either Seoul-Incheon or Los Angeles. Korea allows sterile transit (provided your luggage is checked through), so you can just walk to the escalator that gets you to the departure area, go through security at the top of it (usually quick), and walk to your departure gate. The US does not allow sterile transit, so you have to go through both customs and immigration, and both often have long queues. This is one reason for avoiding travel through the United States.
Sterile transit is almost always a good option if it is available. Many travellers will arrange filights to take advantage of it — in the example flying via Korea rather than via the US and choosing flights that allowing checking luggage through so they can have sterile transit in Korea — even when this costs a bit more.
Many countries offer visa-free sterile transit to a usually long list of "friendly" countries, but still require visas for those from a others. Sterile transit is only available if the airport as well as the country offers it – generally it is only available in large airports that have many transiting passengers every day.
In most airports sterile transit is only available if your arriving and departing flight are on the same ticket and your bag is checked through to your final destination. This may exclude flights on budget airlines, and also may be more expensive than buying separate tickets for each leg. Although there a few exceptions, normally both your arriving and departing flight have to be from the same airport – check for airside transfer arrangements if they use different terminals in the same airport.
For example, at Seoul-Incheon Airport in South Korea, sterile transit is possible provided your luggage is checked through beyond Korea. However, if you are flying in on one airline and out on another and the two do not have an agreement that lets you check luggage all the way, then you need to claim your baggage, go through customs and immigration, then check in for the outgoing flight. In most cases this will mean you need the K-ETA (Korean Electronic Travel Authorisation), see South Korea#Entry requirements for details.
Although you avoid the entry formalities and cost and hassle of a visa, it is likely that an official will still take a quick look at your passport. Similarly your baggage doesn't have to go through a full customs inspection, but there are still limits on what you can take with you (which can be different from your destination). For instance, Singapore's notoriously tough drug laws also apply to passengers on sterile transit, and there have been cases of travellers getting arrested and executed for drug trafficking while changing flights at Changi Airport.
There may be time limits on how long you can spend in transit. Check with your airline if you have more than 12 hours between flights, as they may assume that you are going to have a brief stopover in town rather than staying airside.
Be aware that although you may be expecting a sterile transit, it is still possible that you will have to unexpectedly enter the country. This could happen if you get ill, or there are technical problems with your departing flight. So you may wish to avoid transits where you need a visa, do not have one and are not eligible for visa-on-arrival. You can still be arrested by local police while on sterile transit if there is an outstanding warrant, or if you are subject to an extradition request.
See also
[edit]On two countries that do not allow sterile transit: