Last checked: July 2026 — sourced against TSA “What Can I Bring?” and the TSA 3-1-1 liquids rule. Re-verify before you fly.
The verdict, in one line
The bottle is not the problem — the water is. An empty reusable bottle of any size goes through the carry-on checkpoint fine. A bottle holding more than 3.4 oz (100 ml) of water will be stopped. Empty it before security and refill on the far side. In checked baggage, full or empty is no issue.
Why empty passes and full doesn’t
The 3-1-1 rule limits liquids in the cabin to 3.4 oz (100 ml) per container, all inside one quart-size bag. Water is a liquid, and a typical bottle holds 17 to 32 oz — far over the limit — so a full or even half-full bottle gets flagged and you’ll be asked to empty or bin it. TSA’s “What Can I Bring?” entry for an empty water bottle confirms the container itself is fine to bring through with nothing in it. Once you’re past screening, the bottle can hold as much water as you like.
| State at the checkpoint | Carry-on | Checked bag |
|---|---|---|
| Empty bottle (any size) | Yes | Yes |
| Bottle with water over 3.4 oz | No — empty it first | Yes |
| Frozen solid ice | Yes, if fully frozen at screening | Yes |
How to pack and get water past security
Drink or dump the water before you reach the scanner, then send the empty bottle through with your bag. Most airports now have refill stations or fountains past security, and you can also ask a cafe or the cabin crew to top you up. If you want cold water ready to go, one option TSA allows is freezing it: frozen liquids are permitted through the checkpoint as long as they are frozen solid when screened. If it has started to melt and there’s liquid pooling, it has to meet the 3.4 oz limit again.
Checked baggage has no liquid limit, so a full bottle there is allowed — but a bottle sloshing loose in a suitcase can leak, so empty it or seal it well.
Flying from the UK, EU or elsewhere
The empty-bottle logic is universal: an empty container is fine anywhere, and it’s the liquid inside that’s regulated. The EU and UK use the same 100 ml cabin limit. The UK is mid-transition — airports with new CT scanners such as Heathrow, Gatwick, Edinburgh and Birmingham now allow cabin liquids up to 2 litres, while Manchester, Stansted, Luton and others still enforce 100 ml (Which?, 2026). Even where 2 litres is allowed you may be able to carry a full bottle, but since the return airport may still cap at 100 ml, the habit that never fails is: fly with the bottle empty and fill it after security.
Whatever the rule on paper, the TSA officer at the checkpoint has the final say on what comes through.
Sources & verification
Every claim on this page was checked against the primary sources below and last verified July 2026.
- TSA — “What Can I Bring?”: Empty water bottle (an empty reusable bottle of any size is allowed through the carry-on checkpoint). tsa.gov/…/empty-water-bottle
- TSA — Liquids rule (a bottle holding more than 3.4 oz / 100 ml of water is stopped in carry-on; checked bags have no liquid size limit). tsa.gov/travel/security-screening/liquids-rule
- TSA — “What Can I Bring?”: Ice (frozen liquids are allowed through the checkpoint if frozen solid when screened; if slushy or melting they must meet the 3.4 oz limit). tsa.gov/…/items/ice
- Which? — UK airport liquid rules: which airports allow 2 litres vs still enforce 100 ml (2026). which.co.uk — 100ml rule at UK airport security
Related rules: The 3-1-1 liquids rule · Toothpaste on a plane · Deodorant on a plane
FAQ
Can I bring an empty water bottle through security?
Yes. An empty reusable bottle of any size is allowed through the carry-on checkpoint. Fill it up after you clear security.
Can I bring a full water bottle in my carry-on?
No. Anything over 3.4 oz (100 ml) of water is stopped at the checkpoint. Empty the bottle before screening and refill past it.
Can I bring frozen water or ice?
Yes, if it’s frozen solid when screened. If it’s partly melted with liquid pooling, it must meet the 3.4 oz liquids limit.
Does bottle material matter — steel, plastic, glass?
No. The material doesn’t change the rule; only whether there’s liquid inside over the limit does.
Can I pack a full water bottle in checked baggage?
Yes, there’s no liquid limit in checked bags — just seal it to avoid leaks. The TSA officer still has the final say at the checkpoint.