It is not illegal to eat peanuts on a plane, but it is increasingly discouraged and subject to strict "courtesy bans" due to the high risk of severe allergic reactions (anaphylaxis) among other passengers. While no federal law in the U.S. or UK prohibits peanuts on aircraft, most major airlines have voluntarily stopped serving "peanuts as a snack" to minimize the presence of dust and residue. If a passenger with a life-threatening allergy informs the cabin crew, the flight attendants will often make a "Public Service Announcement" (PSA) asking all passengers in the vicinity to refrain from opening or consuming peanut products for the duration of the flight. In some cases, a "buffer zone" of several rows is established around the allergic individual. In 2026, travelers are encouraged to choose "nut-free" snacks out of respect for their fellow passengers' safety. If you do choose to bring your own peanuts, be aware that you are legally required to follow the crew's instructions; if they ask you to put them away for safety reasons and you refuse, you could be cited for "failing to obey crew member instructions," which is a serious federal offense.