Question: Can I Bring Duty-Free Liquors and Perfumes Into the U.S. as Carry-On Items?
Yes and no.
The Transportation Security Administration (TSA) rigorously enforces its regulations pertaining to transportation of liquids, gels and aerosols in carry-on baggage. Any item containing more than three ounces of product must be transported in checked baggage once you arrive in the U.S.
This means that you can purchase duty-free liquid items (perfume, liquor, etc.) at a duty-free shop outside the U.S. and put them in your carry-on baggage for the international leg of your trip only. If you are changing planes in the U.S., you will need to put those duty-free items in your checked baggage after you clear customs at your point of entry, regardless of packaging.
For example, a traveler flying from Cancún, Mexico, to Baltimore, Maryland via Atlanta's Hartsfield-Jackson International Airport could purchase duty-free items in the Cancún International Airport's shopping area and take these items to Atlanta in the passenger cabin. However, once that passenger clears customs in Atlanta, any liquid, gel or aerosol items larger than three ounces will need to be placed in checked baggage before boarding the flight to Baltimore. Otherwise, TSA officials will confiscate the bottles.
Of course, placing bottles of duty-free liquor or perfume in your checked baggage is a risky enterprise. You will need to plan ahead, leaving plenty of room for your duty-free items. You may also wish to bring wrapping materials, tape and plastic bags to secure breakable bottles. Alternatively, you could purchase protective packaging, such as the WineSkin or BottleWise bag, before your trip and seal your liquor bottles in cushioned plastic wrapping.