Keep essentials in your carry-on

Summary

This pattern is for travellers who check luggage. It describes what to keep in the bag that stays with you, so a delayed or lost suitcase is an inconvenience rather than a crisis.

Recommendation	Why?
Keep all medication in your carry-on, in its original packaging, with a copy of your prescription or a letter from your doctor.	You may need it on the way, and labelled packaging and a prescription help at security and customs.
Bring a few days’ more medication than the trip needs.	Delays happen, and some medicines are hard to get, or are controlled, in other countries.
Keep passports, tickets, cards, cash and insurance details on you or in your carry-on.	You need them at every step, and they’re the hardest things to replace.
Carry valuables, electronics and chargers in the cabin.	Checked bags are handled roughly and are more likely to go missing.
Put power banks and spare lithium batteries in your carry-on, never in checked luggage.	Airlines generally require this because battery fires are easier to deal with in the cabin; check your airline for size limits and rules on using them in flight.
Pack one change of clothes and basic toiletries.	If your bag is delayed, you can still sleep, wash and get through the first day.
Follow the liquids rules for your departure airport and pack liquids in a clear bag at the top.	Rules differ between countries and airports, and having them ready speeds up security.
Check the airline’s size and weight limits for cabin bags.	Over-limit bags may be taken off you at the gate and checked, along with everything in them.

Context

This pattern suits flights with checked luggage, as well as long-distance trains, buses and ferries where bags are stored away from you.

It does not suit carry-on-only travel, where everything is already with you, but the battery, medication and liquids advice still applies.

There’s a trade-off between a light carry-on and being self-sufficient. Every essential adds weight to a bag you carry all day. This pattern keeps the carry-on to things that are hard to replace or needed in the first 24 hours, and leaves everything else in the hold.

Usage

When packing: mark carry-on items on your packing list so they go straight into the right bag. Keep medication, documents and electronics in the same pockets every trip so you can check them at a glance.

For documents: carry the originals and keep copies separately, see Back up your travel documents.

For long flights: add an eye mask, earplugs, a water bottle (empty through security) and a warm layer. These help you rest and adjust on arrival, see Shift to local time quickly.

References

Your airline and the security authority at your departure airport publish the current rules on liquids, batteries and cabin bag limits. Your pharmacist or doctor can advise on travelling with medication, and the embassy of the country you’re visiting can tell you whether a medicine is restricted there.