Do I need a transit visa? Your guide to paperwork for layovers abroad

Certain countries have some pretty demanding visa requirements and processes for U.S. visitors. But what if you're just stopping over for a few hours to catch a connecting flight to your final destination?

The majority of countries that require Americans to secure visas as tourists are fine with foreigners spending a little time at the airport without any extra paperwork, as long as they don't venture outside the international airport terminal. But if there aren't any airport nap pods and you want to rest, even just at the airport hotel, you're probably going to need a visa.

Below are the transit visa policies for some of the most-visited countries where U.S. citizens might have to take a few extra steps to make sure they're on solid, legal footing when passing through.

Australia: You do need a visa if Down Under is your destination, but not if you’re just in transit and will be in the country for less than 72 hours. Another way to look at it: A three-day, visa-free vacation stopover is possible.

Brazil: If you're not setting foot outside the airport's international terminal during your stopover/layover/connection, you don't need a visa.

China: As of September 2013, China grants a bunch of foreign nationals (including Americans) a generous 72-hour visa-free transit period. Travelers have to be landing in certain airports and can only spend their visa-free stopover time in certain cities, but that includes all the biggest metropolises, about 15 in total. Lucky at One Mile at a Time has tips on how to milk the 72-hour free pass, including advice on staying firm even when agents might fight you about whether you need a visa.

India: If you have to leave the international terminal for your connecting plane, train or automobile, you need a transit visa.

Iran: Regardless of your layover situation, a transit visa is required. The country may be opening more to international tourists, but setting foot in Iran for any amount of time still requires jumping through hoops.

Russia: If your layover exceeds 24 hours or you need to switch airports or leave the one where you land, then you need a transit visa.

Vietnam: No visa needed if you plan to stay firmly planted in the airport. If you want to venture out, you'll need to get a single-entry visa arranged ahead of time.