Split the costs where you planned the trip.
Log what everyone paid as you go, in whatever currency they paid it in. JourneyComposer works out who owes whom and reduces it to the fewest transfers that settle the whole trip.
At a glance
Any currency, one answer
Log each expense in the currency it was actually paid in. Settle in a single currency, or keep the balances separate per currency.
Splits that match reality
Split evenly, leave someone out, or weight a share when one person had the room to themselves. Planned costs stay out of the settlement until they are actually paid.
Attached to the trip, not a separate app
The costs sit next to the itinerary they belong to, so an expense can point at the stop it happened on.
Log it in the currency it was paid in
Somebody pays for the hotel in euros, somebody else buys the train tickets in francs, and a third person covers dinner in pounds. Recording all of that in one currency means converting as you go and arguing about rates later.
Here each expense keeps its own currency. At the end you either settle in one currency, with the conversion applied once, or keep a separate balance per currency and settle each. Both are exact, and neither requires anyone to do arithmetic on their phone at an airport.
Not everything is split evenly
Most expenses are shared by everyone, so that is the default. But one person took the single room, two people skipped the boat trip, and somebody's partner joined for three days in the middle. Each expense can be split across exactly the people it was shared by, with a heavier share for anyone who used more of it.
Costs you expect but have not paid can be logged as planned, so the budget is visible without polluting the settlement. They join the settlement the moment you mark them paid.
Settling up at the end
With five people and three weeks of expenses, everybody owes everybody a little. JourneyComposer collapses that into the smallest set of transfers that clears every balance, so the group makes three payments rather than eleven.
The record survives the group. If someone leaves the trip or deletes their account, the expenses they paid stay intact with their name on them, because a settlement that silently rewrites itself when one person leaves is worse than no settlement at all.
Questions
Does everyone need an account?
Everyone you want to split costs with needs to be a member of the trip, which means a free account. People following along on a read-only share link do not see the costs.
Can I use it for a trip I planned somewhere else?
Yes. A trip can be as thin as a name and a few travellers if all you want from it is the cost splitting, though most people end up planning the rest here too.
What happens to shared expenses if I delete my account?
Expenses on a shared trip are kept, with the name you used, so the other travellers' settlement stays correct. Everything else you own is deleted with the account.
Stop keeping the group's money in a note app.
Add the trip, add the travellers, and log the first expense in under a minute.