Most bill splitters give you one number. It nets what you owe against what you are owed, then shows the difference. The number is small, and it feels tidy.
It also hides the work.
One number hides two jobs
Say you owe Aida 40 dollars, and Ben owes you 45 dollars. A netted view shows “+5”. That number is true, and it is useless. You still have to pay Aida. Ben still has to pay you. Two payments must happen, and the netted view names neither of them.
Penny shows both totals instead:
- You owe 40 dollars.
- You are owed 45 dollars.
Each total is grouped by currency. Neither one cancels the other.
Netting across groups is worse
The problem grows when you belong to more than one group. A netted total mixes your ski trip with your flat share. Those are different people and different debts. Clearing one does nothing for the other.
Penny keeps groups apart. It never combines the balances of two groups, and it never converts between their main currencies. A group is the boundary.
Simplification is a separate idea
Reducing the number of payments is still worth doing, and Penny does it. Inside one group, it finds the smallest set of transfers that clears every debt.
That is not the same as netting. Simplification changes who pays who. It never changes who owes what. Your balance stays exactly as the bills recorded it.