International trips make expense splitting harder because people pay in different currencies at different exchange rates. The cleanest system is to choose one base currency for the group and convert expenses when they are added.
Choose a base currency
Pick the currency everyone wants to settle in, such as EUR, USD, or GBP. This keeps the final balance readable even when the trip includes local cash, card payments, and online bookings in different currencies.
Record the original currency
Keep the original amount and the converted amount. That makes receipts easier to verify and helps travelers understand how a local purchase affected the shared balance.
Avoid manual exchange-rate debates
Manual conversion can create small disagreements, especially on long trips. A consistent conversion method is more important than chasing a perfect rate for every coffee or taxi.