In an open-end consumer lease, assuming that you have met the mileage and wear standards, the residual value is considered unreasonable if it exceeds the realized value by more than three times the base monthly payment (sometimes called the "three-payment rule"). If you believe the amount owed at the end of the lease term is unreasonable and refuse to pay, the lessor or assignee may attempt to prove that the residual value was reasonable when it was set at the beginning of the lease. However, if you cannot reach a settlement with the lessor or assignee, you cannot be forced to pay the excess amount unless the lessor or assignee brings a successful court action and pays your reasonable attorney's fees.