What Should Always Be in Your Carry-On

Everything in this list shares one property: replacing it at the destination is either impossible, expensive, or requires a pharmacy that is closed at midnight.

• All prescription medication, in original packaging, in more than the quantity you expect to need
• Passport, visa documents and one printed copy of the photo page
• Payment cards, split between two locations on your person or bag
• Phone, charger and a power bank
• One complete change of clothes and underwear
• Spectacles or contact lenses plus solution
• Keys to your home and your car
• Anything irreplaceable: laptop, camera, jewellery, documents

The 100 millilitre rule remains the international standard. Some airports have installed new CT scanners that allow larger volumes, but the rollout is uneven, and rules can differ between terminals at the same airport.

Medically necessary liquids, baby milk and formula are exempt from the volume limit in most jurisdictions, but they must be declared and are usually screened separately.

Lithium batteries are the item most likely to cause a problem at the gate, because the rules are strict and inconsistently explained.

• Power banks must travel in the cabin, never in checked baggage
• Under 100 watt hours is generally fine without approval
• 100 to 160 watt hours usually needs airline approval in advance
• Spare loose batteries should have their terminals taped or be in individual bags
• Some carriers now require power banks to remain visible and not be used in flight

Our lithium battery rules guide covers the watt hour calculation and the airline-by-airline differences in more detail.

If you are ever going to spend an unplanned night in a terminal or an airport hotel, these small items are what make the difference.

• Toothbrush and travel toothpaste
• Deodorant in solid form, which does not count against the liquid allowance
• Earplugs and an eye mask
• A thin layer such as a merino long sleeve, since terminals are cold at night
• A refillable water bottle, empty through security
• Two snacks that are not chocolate

Screening delays are almost always caused by repacking. A bag organised for the tray table means you unpack in one movement and repack in another.

1. Liquids bag in the outermost pocket, not buried
2. Laptop and tablet in a single slim sleeve you can lift out together
3. Power bank and cables in one pouch, easy to show if asked
4. Documents in an inside pocket you can reach without opening the main compartment
5. Clothes and everything else compressed at the bottom

• Putting medication, keys or chargers in the checked bag because the cabin bag was full
• Carrying a power bank in the hold, which is prohibited on every airline
• Packing exactly to the liquid limit with no allowance for a stricter return airport
• Filling the water bottle before security rather than after
• Forgetting that the cabin bag has a weight limit as well as a size limit