Your quart-size liquids bag must be able to zip closed completely and comfortably. TSA's "3-1-1" rule requires that all containers be 3.4 ounces (100ml) or less and fit into a single, clear, quart-size plastic bag. If the bag is bulging so much that it won't seal, or if you have to use tape or rubber bands to keep it shut, a TSA agent may require you to discard some items. The bag should be "resealable," meaning you can open and close it during the screening process if an agent needs to test a specific bottle. In 2026, while many airports have upgraded to CT scanners that allow you to keep liquids inside your carry-on, the quart-size limit still applies. A good rule of thumb is that the items should lie relatively flat; if you have to "squish" the bag to get the zipper to move, you are likely over the limit. Remember, the rule is about the container size—a half-empty 6oz bottle is not allowed, even if the liquid inside is less than 3.4oz.