The 3.4oz liquid limit has been the defining annoyance of US airport security since 2006, and it might finally be cracking. According to senior administration officials, the TSA is actively considering letting PreCheck travellers carry water bottles through checkpoints, with a rollout possible within months at select airports.
The catch is technology. Only checkpoints with newer CT scanners — the kind that can automatically tell water apart from other liquids and flag actual threats — would participate. Since those machines can clear a bottle without manual inspection, the rule would only work where they're installed, and not every airport has them even in PreCheck lanes. The familiar 3-1-1 rule (one quart-size bag, containers under 3.4oz) stays in place everywhere else, and other liquids like sodas, soups or cosmetics wouldn't be included.
A water bottle sounds modest, but the context is interesting. In 2024 the TSA said it had no plans to loosen liquids rules until roughly 2040, when next-generation screening would be fully rolled out. That timeline started shifting in 2025 under then-Homeland Security Secretary Kristi Noem, who scrapped the shoe-removal rule and publicly questioned the liquids ban itself, hinting a bigger announcement on liquid sizes could follow. Nothing is guaranteed yet, but this is the most concrete sign of movement on the rule in two decades.
It would also bring the US closer to what's already happening in Europe, where the EU has relaxed liquids rules airport by airport depending on screening capability — producing the familiar patchwork where you can board with a full bottle in one city and dump it in the next. That inconsistency is exactly what US travellers might need to brace for too: whether you can keep your water could depend on which terminal and which lane you're in.
For travellers, the practical takeaway is straightforward. If you hold PreCheck and fly through major hubs with modern CT scanners, you may soon skip the airport newsstand markup and the awkward empty-bottle routine. Everyone else shouldn't pack their hydration hopes just yet — and even PreCheck travellers should expect a transition period of differing rules between airports. PreCheck itself costs around $78 for five years if you've been on the fence, and membership already buys shorter lines and no shoe or laptop removal at most airports. A possible water-bottle exemption would be a small bonus, but the wider lesson is that security rules are softening faster than the official 2040 timeline suggested, which could reshape what a pre-flight airport visit looks like over the next few years.