01The rules in detail
An empty reusable bottle passes security anywhere. A full one over 3.4 oz / 100 ml will be confiscated unless you drink or dump it first. Frozen water is allowed by TSA only if completely solid at screening. Bottles bought after security can go on board; some countries (Australia, some EU transfer points) re-screen liquids at connecting airports.
02Tips
- Carry it empty; fountains are common airside in the US, Europe and Asia.
- Insulated bottles are fine — just open the lid for inspection.
03Frequently asked
Can I bring a water bottle in my carry-on?
Yes, with limits. Empty bottles are fine; filled bottles over 100 ml must be emptied before security. Fill up at a fountain airside.
Can I pack a water bottle in checked luggage?
Yes. Empty bottles are fine; filled bottles over 100 ml must be emptied before security. Fill up at a fountain airside.
Are the rules the same outside the US?
Mostly similar for liquids and batteries, which follow international standards, but sharp objects, tools, lighters and self-defense items vary widely by country. Check the departure airport's rules and the destination's laws.
TSA and other agencies allow officers to refuse any item they judge unsafe, and rules change. This page summarises published guidance as of the verified date; confirm on tsa.gov or your airport's site before packing anything unusual.