Direct answer
Prevent mileage fraud with GPS road-distance verification, session-linked claims, duplicate detection, commute exclusion rules, and MobiTraq alerts when submitted expenses exceed verified distance.
The five most effective mileage fraud controls:
1. **GPS road-distance** — verified totals, not employee estimates
2. **Shift session linkage** — every mile tied to active work period
3. **Expense correlation** — flag claims exceeding verified distance
4. **Duplicate prevention** — session IDs block repeat submissions
5. **Manager route replay** — visual audit before approval
Organizations using GPS verification report 5–15% reduction in mileage reimbursement costs.