After your items and carry-on bag have gone through security, you can fill up your water bottle at a nearby refilling station. If you bring your full water bottle to the security checkpoint, it's not a big deal. A security person will simply have you dump it before it can go through the checkpoint.

Yes, you can refill your water bottle on a plane in 2026, but there are a few "pro-traveler" logistics to keep in mind. While most modern aircraft are equipped with potable water tanks, many flight attendants and frequent flyers recommend against drinking directly from the galley taps or bathroom faucets due to varying tank cleanliness standards. Instead, a high-value strategy is to ask a flight attendant to fill your reusable bottle from their large 1.5-liter bottled water supply or the filtered water dispenser in the galley. Some ultra-long-haul aircraft, like the Boeing 787 Dreamliner or Airbus A350, now feature dedicated self-service water stations for passengers. It is a peer-to-peer essential to bring your bottle empty through security and fill it at an airport "hydration station" before boarding; this ensures you have a full liter of water for takeoff, which is the most dehydrating part of the flight, without having to wait for the cabin service to begin in the middle of a busy ascent.