1. Not tracking small expenses. The little things add up! Always log every purchase, no matter how minor.
2. Forgetting about tax and service charges. Don’t leave anyone stuck with hidden costs—include tips, delivery fees, and surcharges.
3. Not communicating cash repayments. "I'll pay you later" is fine—but always update your shared totals so debts don't cause confusion.
4. Not double-checking the split before paying out. Errors in math (or mis-typed numbers) can cause resentment—always check before settling up!
5. Making assumptions about fairness. Always discuss expectations and use a tool (like RoomMate Cost Splitter) to avoid misunderstandings.

With the right attitude, a little transparency, and a clear calculator, everyone can feel good—and debt-free—at the end of every month.