How to split trip costs without the awkward messages
Write down who paid what as you go, settle in the fewest payments, and keep the money between you. Works in any currency.
Money is the part of a group trip people remember for the wrong reasons. Not the amounts, which are usually small, but the six messages it took to settle them and the one person who never quite paid. A little structure in the first hour fixes most of it.
Say the rule before the first dinner
Decide, out loud, how the trip is split. Even shares is the default and works for most trips. Say what is shared (the house, the car, the group dinners) and what is not (one person's spa afternoon, the flight each person booked). The rule said on day one is a plan. The same rule on day five is an argument.
Write it down the same day
Whoever pays writes it down that evening: what it was, how much, and who it covered. Not a receipt photo in a chat where it scrolls away, and not a memory. One list, kept by one person, that everyone can see. Round numbers are fine. Nobody is auditing.
Keep each currency on its own
On a trip abroad you will pay in two currencies: the flight and the car hire in your own, the dinners and the taxis in the local one. Do not convert. Settle each currency on its own and let each person's card do the exchange it was going to do anyway. Converting at a guessed rate is where the small arguments come from.
Settle in the fewest payments
Add up what each person paid and what their share should have been. The people who paid more than their share are owed; the rest owe. The biggest debt pays the biggest credit first, then the next, until everyone is even. Four people rarely need more than three payments. Doing it any other way, where everyone pays everyone, is how a weekend ends with eleven transfers.
Send the amount, not a request to work it out
When you ask, send the exact amount and the one tap that pays it: a Venmo or PayPal link with the number filled in, or the bank details and a reference. A message that says "you owe me something for the house" gets ignored. A message that says "$41.50, here is the link" gets paid in the car on the way home.
What stays off the list
The money never needs to pass through anyone. Nobody should hold the group's cash, and no app needs to sit in the middle taking a cut. The payments go straight between the people who owe them.
Put it into practice
The planner's Costs tab does the arithmetic. Add the people on the trip, then each cost as it happens: what it was, who paid, the amount, and the currency. It keeps each currency separate, works out who pays whom in the fewest payments, and shows a button for each one: Venmo for dollars, Cash App for dollars or pounds, UPI for rupees, PayPal for most currencies, or a copy of the bank details with the amount and a reference. Each person adds their own handles once. The money goes straight between you and never passes through TripDeputy.