1. Automatically fill in an exchange rate that the employee cannot obtain on the open market. Force employee to manually enter exchange rates for every transaction to avoid losing money.

2. Deny hotel nights or car rental expenses due to "lost" receipt. Don't tell employee and assume they won't check reimbursement checks. Many do not.

3. Modify expense rules to deny claims to the point that line managers complain.

These are the frauds I have seen.