Travel wallet checklist: what to carry abroad, what to leave behind
The instinct before a trip is to add: an extra card in case one fails, the loyalty cards for the airline, some emergency cash, the insurance paperwork. By day two you are carrying a fat wallet through a city where a fat wallet is the most visible thing about you.
The better model is subtraction plus separation. Carry less, and split what remains across two places.
What goes on your body
One debit or credit card that you have told the bank about. One backup card on a different network, because Visa and Mastercard acceptance is not identical everywhere and neither is your bank's fraud system. Enough local cash for a day, including small notes for taxis, tips and the places that still do not take cards.
Your ID as required locally - in much of Europe a driving licence or ID card is fine, and your passport can stay behind. One transit card if the city uses them.
That is the whole list. The general version of this audit is in what to keep in your wallet, and travel only tightens it.
What stays in the room
Passport, unless the country legally requires you to carry it or you are travelling that day. A third card. The bulk of your cash. Insurance documents, which should also exist as photos in your phone and in your email. Anything with your home address on it.
The point of separation is that a single bad moment - a bag snatched, a pocket picked - costs you an afternoon rather than the trip.
Where you carry it matters more than what you carry
Front pocket, always, and preferably a front pocket with the wallet lying flat rather than standing proud. Back pockets and open bag pockets are where the overwhelming majority of pickpocketing happens, and the specific techniques used are described in how to avoid pickpockets in Europe.
A slim wallet helps here for an unglamorous reason: it is the only kind that actually fits a front pocket comfortably, which means it is the only kind you will keep putting there. A flat cardholder with a zipped coin pocket handles the euro coin problem without adding a second item, which is worth more on a trip than it sounds - the argument is in the euro coin problem.
Prepare for the version where it goes wrong
Before you leave, photograph the front of every card you are carrying and store it somewhere you can reach without your phone - an email to yourself works. Save your bank's international number as a contact, because the freephone number will not work from abroad. Know how to freeze a card in your banking app.
A tracker card in the wallet covers the most common outcome, which is not theft but leaving it on a café table. The full recovery sequence, in the right order, is in what to do in the first hour after losing your wallet.
The rule that makes it stick
Pack your travel wallet the night before, not at the airport. Take everything out, put back only the list above, and leave the rest at home rather than in a bag you are carrying anyway. A wallet you emptied deliberately stays empty; one you meant to empty does not.