Bet You Didn't Know JetBlue Flights Are Bring Your Own Bottle 

This article originally appeared on Travel + Leisure. 

As airlines charge fees for more and more services, most people will look to save a couple bucks wherever they can. And it turns out that one place passengers can save money is alcohol.

There’s a little loophole used by JetBlue that allows passengers to drink alcohol they’ve brought onboard the plane.

Technically, according to FAA regulations, passengers can bring alcohol onboard — they just can’t open it themselves.

FAA rules state that only “the certificate holder operating the airline” is allowed to open and serve alcoholic beverages on board. If a passenger wants a drink of their own alcohol on a JetBlue flight, they must ask a flight attendant to serve them.

Although it may seem like a minor technicality, it’s a pretty important one. Because of well-documented issues with intoxicated passengers on planes, it’s part of the flight attendant’s duties to assess each drinking passenger’s sobriety levels. A flight attendant can stop serving at any time — even if a passenger brought their own alcohol and has a full bottle left.

There are also some rules regarding the types of alcohol passengers can bring on the plane. If they’re bringing alcohol from home and it must pass through security, bottles must be smaller than 3.4 ounces and be sealed in a plastic baggie with other liquid items. For those who buy alcohol at the duty-free, JetBlue “will allow alcoholic beverages not more than 24% alcohol by volume, or more than 24% by volume and not exceeding 70% alcohol by volume, when in retail packages.” Nobody can bring more than five liters of alcohol on the plane.

Passengers can try the hack on other airlines by asking flight attendants to pour alcohol they brought from home. Most will not, but it doesn’t hurt to ask.

But for those who are tempted to just do it themselves, pouring alcohol yourself or topping off a drink could lead to a host of trouble — like police waiting at the airport when the plane lands.