• Liquids, gels and aerosols that are 3.4 ounces (100mL) or less and fit in a clear, sealable one quart-size (liter-size) bag are allowed. You may have to take them out at airport security so they can be screened separately.
• Baby formula, milk (including breast milk), baby food, juice and liquid/gel medications larger than 3.4 ounces may be allowed on board, but they will have to be screened separately. If you’re traveling with any of these items, let the TSA agent know.
• Items larger than 3.4 ounces purchased inside the airport after security in the U.S., like drinks or toiletries, are allowed on the plane. If you have a connecting flight and have to go through security again, you may not be able to bring the larger items with you.
• If you’re flying into the U.S. from another country and have a connecting flight, you may be able to bring liquids bigger than 3.4 ounces if you bought them at a duty-free store. They must be stored in a special sealed bag. Some bottles are hard to scan. If your liquids cannot be scanned properly, you will have to put them in your checked bag or throw them away.

The rules for liquids, gels and aerosols are different in every country. Visit the website of your departure airport for more information.

If you don’t have TSA PreCheck, you’ll have to take your laptop out of your bag and place it into a separate bin for x-ray screening.

Plastic knives and round-bladed butter knives are allowed in carry-on bags. All other types of knives must be put in your checked bags.

Gifts and packages are subject to the same inspection rules as your carry-on bags. If you're traveling with gifts, you should unwrap them so they're easier to screen.

You’re not allowed to bring anything on board that can change or limit the functionality of any aircraft structure, seat assembly, or tray table.

The U.S. Department of Homeland Security (DHS) uses additional security measures for all international flights to the U.S. They include screening with questioning of some or all travelers, as well as extra screening of larger electronic devices.

If you are flying internationally, you should try to get to the airport check-in counter three hours before your flight to allow time for the additional security.

For more information, visit the DHS website.