Track every shared expense noting who paid and who participated. Each person's share equals the sum of their portions of each expense, not just a simple total-divided-by-headcount. For unequal participation (e.g., only 3 of 5 people did the excursion), split that expense only among participants.
- Track who paid each expense and who benefited from it
- Split each expense only among those who participated
- Total each person's paid amount minus their owed amount = their balance
- Positive balance = others owe them; negative = they owe others
- Use minimum-payment settlement to reduce the number of transactions
| Method | Best For | Fairness | Complexity |
|---|---|---|---|
| Equal split | Similar participation | Low | Simple |
| Per-expense split | Varied participation | High | Moderate |
| Proportional | Income differences | Very high | Complex |
| One pays, split later | Small groups | Medium | Simple |