Abstract: A mileage verification system (10) for a vehicle (100) having an odometer (14), the mileage verification system (10) comprising primary and secondary units (12a, 12b) in the vehicle (100) for monitoring mileage travelled by the vehicle (100), the primary unit (12a) being interfaced with the odometer (14) for gathering one set of vehicle mileage data, and the secondary unit (12b) being adapted for gathering another set of vehicle mileage data, independent of the odometer (14); verification means in communication with both units (12a, 12b) for comparing the sets of vehicle mileage data gathered and determining inconsistencies; data storage means (20) in communication with both units (12a, 12b) for storing the vehicle mileage data gathered; communication means (12c) for enabling communication i) between the primary unit (12a) and the verification and data storage means (26, 20), and ii) between the secondary unit (12b) and the verification and data storage means (26, 20); an authentication system for authenticat