Crossing a border adds a category of things that a domestic trip never needs: documents, power compatibility, payment that works abroad, and access to information when your phone has no signal. This list covers that layer rather than repeating clothing basics.
Documents, and copies of documents
Documents are the category where a mistake ends a trip rather than inconveniencing it. Check the requirements for your specific passport and destination — they differ by nationality, not just by country visited.
Passport with enough remaining validity — many countries require six months beyond your entry date, and some require blank pages.
Visa or electronic entry authorization, where your nationality needs one.
Proof of onward travel and accommodation, which some countries ask for at the border.
Photos and paper copies of your passport, stored separately from the passport itself.
Driving licence and an international permit, if you intend to drive.
Vaccination certificates, where the destination requires them for entry.
Power: adapters and voltage
Two separate issues are often confused. The plug shape determines whether a device physically fits the socket; the voltage determines whether it survives being plugged in.
Most phone, laptop, camera, and tablet chargers accept 100–240 V and need only a plug adapter.
Hair dryers, straighteners, and some shavers are frequently single-voltage. Check the label — if it says 120 V only, a converter is needed, not just an adapter.
A single multi-country adapter with USB ports usually replaces several separate items.
Sockets in your accommodation may be scarce or awkwardly placed; a short multi-socket cable or a power bank covers that.
Money that works abroad
Two cards on different networks, stored in different places, so one loss is not total.
A card without foreign transaction fees, if you have one.
A small amount of local currency for transport, tips, and places that do not take cards.
Your bank notified of travel dates, if your bank still requires it.
A habit of choosing to be charged in the local currency rather than your own at card terminals, which is normally the better rate.
Medication across borders
Carry medication in its original labeled packaging, in your carry-on, with enough for the whole trip plus a few days. Bring a copy of the prescription or a letter from your doctor.
Some medications that are routine in one country are controlled or prohibited in another. Check the rules published by your destination before you travel, and speak to a healthcare professional about anything you are unsure of.
Connectivity and offline backups
An eSIM installed before departure, or a confirmed roaming plan for the destination.
Offline maps downloaded for the cities you will be in.
Boarding passes, tickets, and accommodation details saved offline, not only in email.
Translation packs downloaded for offline use, if there is a language barrier.
Emergency numbers, insurance details, and your embassy contact written down on paper as well as stored on the phone.
Frequently asked questions
What documents do I need for international travel?
A passport valid well beyond your return date, any required visa or entry authorization, and proof of onward travel or accommodation where it is asked for. Keep digital and paper copies separate from the originals.
Do I need a voltage converter or just a plug adapter?
Most phone, laptop, and camera chargers accept 100–240 V and only need a plug adapter. Hair dryers, straighteners, and some shavers are often single-voltage and can be damaged without a converter — check the label on the device.
How many months should be left on my passport?
Many countries require at least six months of validity beyond your entry date, and some require blank pages. Check the rule for your specific destination well before you travel, because renewals take time.
What should I do about money abroad?
Carry two cards from different networks stored in different places, tell your bank where you are going if it still requires that, and keep a small amount of local cash for transport and places that do not take cards.