What to agree before a group trip, so settling up stays friendly

Published September 27, 2026 by the developer of SplitWithUs (about)

Arguments about trip money are rarely about arithmetic. They start when two people had different rules in their heads and only find out at the end, when the total is already large and everyone is tired. A few minutes in the group chat before leaving settles most of these questions while they are still hypothetical and cheap.

Where the disagreements start

Even split or what you used. The friend who does not drink, paying an equal share of every round. The one who skipped the expensive dinner.
People who join late or leave early. Do they share the car hired for the whole week? The nights in the apartment they were not there for?
Personal or shared. Souvenirs, a single-room upgrade, a pharmacy run. Obviously personal to one person, arguably shared to another.
Fees. Foreign transaction fees and ATM fees land on whoever used their card. Are they part of the trip, or the cost of that person's choice of card?
Exchange rates. Nobody thinks about them until someone notices the currency moved. The guide on which exchange rate to use covers the options.
Loans between two people. Paid back on the spot, or netted at the end? Doing both makes someone pay twice; see when one friend pays for another.
Timing. Settling months later, when nobody remembers what the receipt from the second night was for.

A short list to agree

The currency the group settles in.
The default split, usually even, and the named exceptions: drinks, rooms, an activity some people are not doing.
What counts as personal and stays with whoever bought it.
Who carries card and ATM fees.
The rate: the day each receipt was paid, or what the card actually charged where someone knows it.
How loans between two people are handled.
Who collects the receipts, and by when the group settles.

A message you can adapt

Example. "Money for the trip: we settle in euros, within a week of getting back. Take a photo of every receipt you pay." "Shared costs are split evenly, except drinks (only the people drinking) and the Saturday boat trip (only the four going). Souvenirs and room upgrades are personal. Card and ATM fees stay with whoever paid them." "Each receipt counts at the rate of the day it was paid, or at what your card charged if you know it. If you cover someone, just put it on the pile; don't pay each other back as we go."

Nothing in it is unusual; the point is that it is written down, in a place everyone saw before any money was spent. When a question comes up at the end, the answer is already in the chat.

How the calculator handles it

In SplitWithUs, the settle currency is set on step 1, and so are the exceptions that keep coming back: make a group for "Drinks", "Boat trip" or "Room A", then pick the group under "Split between" on each receipt instead of ticking names every time. Someone who joined late is simply left out of the receipts from before they arrived. The rate rule above is the one the calculator applies by default, as the methodology page explains.

Limits

This is a way to set expectations between friends, not a contract. People can still change their minds; the list just makes it clear what the starting point was.
Some choices here are about fairness, not maths: whether the non-drinker should pay for the taxi to the bar, for instance. A calculator can apply any rule you pick, but it cannot pick one for you.