The Transportation Security Administration's list of prohibited items is ever-evolving, but as of August 2013, liquor wasn't on it. Alcoholic beverages with more than 70 percent alcohol are prohibited in checked luggage, however. For some perspective, 70 percent alcohol translates to 140 proof; most common liquors, such as whiskey and vodka, are around 80 proof. Certain popular brands of rum are 150 proof and aren't allowed. The TSA rules about bringing liquor and other alcoholic beverages onto a plane differ between carry-on luggage and checked baggage.
The same rules apply for alcoholic beverages in carry-on luggage going through a TSA security screening checkpoint as for other liquids. It's known as the 3-1-1 rule: all allowable liquids must be in containers of 3.4 ounces or less and placed inside 1 one-quart-sized clear zip top bag. The traditional mini bottles of liquor served on airlines fit the 3-ounces-or-less criteria. Any closed container liquor you purchase after clearing the security screening is also allowed on board, according to the TSA.
Putting bottles of liquor inside your checked luggage isn't a good idea for one main reason: baggage handlers throw luggage around as a job duty, without concern that, say, an expensive and rare bottle of Chilean pisco might be inside it. Bottles are known to break under such conditions, so mail it home, if possible. If mailing it home isn't an option, the TSA allows up to five liters of sealed beverages containing an alcohol content between 24 and 70 percent -- 48 to 140 proof. Anything below 24 percent -- generally wine and beer -- isn't regulated by the TSA concerning checked bags.
If you decide to mix your own drink instead of ordering it from the flight attendant, you might be in water hotter than a toddy. Airlines have different policies regarding the consumption of alcohol on board their planes. Rather than breaking out your own mini bottles mid-flight, airlines would rather you pay for the liquor they provide. Some even forbid the consumption of alcohol they don't sell you. Learn the rules and regulations of your flight provider before going the BYOB route at cruising altitude.
Even though the TSA may let you bring up to five liters of liquor in your checked luggage, if you're flying internationally, you may not be able to bring it past customs when you arrive at your destination. When flying back to the U.S., you must declare anything you didn't have when you left. You're only allowed to bring one liter of alcohol into the country, in most cases, according to U.S. Customs and Border Protection rules. And even though you may have bought that bottle duty-free in one country, you could still be required to pay taxes on it when bringing it into another.
