How live exchange rates affect group trip settlements
Last updated by The EvenRound team.
The dollar rallied 3% during your week in Tokyo. Did your trip suddenly cost everyone more?
FX rates move. During a typical week-long international trip, EUR/USD might move 0.5-2%; in a volatile period it can move 5%. For a €4,000 group trip, a 2% rate move is €80 - small but not nothing. The key question is: who eats the FX risk during the trip?
The two models
Snapshot model: each expense is converted at the rate on the day it was logged. The group's running balance in their settlement currency stays stable; FX risk is borne by the actual payer at the moment they paid. Live model: balances are recomputed at settlement using the rate that day. FX risk is shared across the group depending on when they settle.
Why the snapshot model is fairer
If Anna paid €40 for a Lisbon taxi on Tuesday and the GBP rate was 0.85, that taxi cost £34 at the time. If Sterling drops 3% by trip-end, the live model would charge each Brit £35 for their share - even though they 'used' £34 of value. The snapshot fixes the cost at the time it was incurred, which matches reality.
Where live rates do help
If you're recurringly settling within a short cadence (e.g., monthly multi-currency rent), live rates approximate snapshots well enough. If your group settles only at trip end and nothing in between, snapshots are clearly superior.
What rate counts as 'live'?
There's no single 'the' rate. The European Central Bank publishes a daily reference rate at 4pm CET. Bloomberg has continuous mid-market. Banks have their own (worse) rates. Wise and Revolut publish their own (close-to-mid-market) rates. For settlement purposes, ECB or mid-market rates are the standard.
How EvenRound handles this
EvenRound snapshots ECB mid-market at the time each expense is logged. That number is stored permanently with the expense - no matter when the group settles. Settle Up runs against the snapshot rates, not live rates. The user's actual money transfer (via Wise, Revolut, etc.) happens at their provider's rate, but the agreed-upon EvenRound amount is fixed.
Snapshotted mid-market rates are the cleanest model for group trips. Live rates add unfairness without adding accuracy. If your app uses live, switch.