You can take liquids in your carry-on luggage on a flight with the following general rules for 2025:

• Liquids must be in containers of 100 ml (3.4 ounces) or less each.
• All these containers must fit comfortably inside one transparent, resealable plastic bag with a maximum capacity of 1 liter (about 20 cm x 20 cm).
• Only one such plastic bag is allowed per passenger.
• The bag must be presented separately at security unless you are flying from certain airports with advanced 3D CT scanners that allow liquids to remain in the bag.
• Liquids over 100 ml are not allowed in carry-on unless they fall under exemptions such as essential medications (with a doctor's note), baby food or formula needed during the flight, or liquids purchased at duty-free shops after security (which must remain sealed until your final destination).
• Containers larger than 100 ml are not permitted even if partially filled.
• Frozen liquids are generally not allowed in carry-on.

Some airports in the UK and Europe (e.g., Birmingham, Gatwick, Edinburgh, Newcastle) have started letting passengers keep liquids in their bags at security due to new scanning technology, but the 100 ml container size limit still applies everywhere. In summary, you can carry up to 1 liter of liquids in total, divided into containers of 100 ml or less, all packed in one clear resealable bag in your hand luggage