When the shipper or consignee pays charges for a transportation service which exceed those applicable under the tariff, a condition of overcharge claim exists. A carrier may make an error and create an overcharge many of the following ways: (1) assessment of an incorrect rate; (2) errors in description on the bill of lading of the bill of lading of the commodities being shipped; (3) errors in weight in which the weight designed on the bill of lading is incorrect, or an incorrect minimum weight is applied; (4) mistakes in tariff interpretation; and (5) clerical errors. Application for an overcharge claim must be filed in writing with the carrier within three years of time of delivery of the shipment. Normally, the claim is filed; the period is then extended six months from the time the claim would be disallowed. This permits the applicant to bring suit in the event application for an overcharge claim was disallowed by the carrier.