Negotiated Rates Act of 1993 - Amends Federal transportation law to authorize persons against whom a claim is made by a motor carrier of property (other than a household goods carrier), or by a nonhousehold goods freight forwarder for the collection of rates or charges in addition to the rates originally collected by such carrier or freight forwarder, to elect to satisfy such claim pursuant to a specified formula upon showing that the carrier or forwarder is no longer transporting property or is transporting property for the purpose of avoiding application of this Act. Requires that the claimant have been offered a rate other than the one legally on file with the Interstate Commerce Commission (ICC), have tendered freight in reasonable reliance upon the offered rate, the carrier or forwarder did not properly or timely file a tariff for the rate or failed to execute a valid contract for transportation services, such rate was collected by the carrier or forwarder, and the carrier or forwarder demands additional payment of a higher rate filed in a tariff. Sets forth as elective satisfaction of such claims payment of the following percentages of the difference between the carrier's applicable and effective tariff rate and the rate originally billed and paid: (1) 20 percent for shipment 10,000 lbs. or less; (2) 15 percent for shipments over 10,000 lbs.; and (3) five percent where the payor is a public warehouseman. Provides that claims against persons from whom the additional applicable tariff rate is sought shall not be liable for the difference between the motor carrier's rate and the rate originally billed and paid if: (1) such person is a small business or charitable organization; or (2) the transported cargo is recyclable material. Makes it an unreasonable and unlawful practice to charge the difference between the applicable filed rate and any rate for a transportation service negotiated before September 30, 1990, if the charging carrier or freight forwarder is no longer transporting property between certain places or is transporting property between such places in order tp avoid application of this provision. Grants the ICC jurisdiction to determine the unreasonable practice. Denies use of the negotiated rate dispute resolution procedure to any person seeking an administrative enforcement by the ICC. (Sec. 3) Shortens the statute of limitations for the filing of claims by: (1) a motor common carrier or freight forwarder for recovery of transportation or service charges; and (2) any person to recover overcharges by a motor carrier. (Sec. 4) Permits motor carriers and shippers to resolve by mutual consent, subject to ICC review and approval, any overcharge and undercharge claims resulting from billing errors or incorrect tariff provisions arising from the inadvertent failure to properly and timely file and maintain agreed upon rates, rules, or classifications. (Sec. 5) Prohibits a tariff filed with the ICC from being held invalid solely on the basis that it: (1) uses a numerical or alpha account code to designate customers or describe the applicability of rates; or (2) does not show a specific rate or designate customers or describe the applicability of rates. (Sec. 6) Requires a motor contract carrier to enter into a written agreement (separate from a bill of lading or receipt) for the provision of transportation services. Sets forth both civil and criminal penalties for violations of this requirement. (Sec. 7) Requires the ICC to issue regulations prohibiting any motor carrier from reducing a rate set forth in its tariff or contract for any person but the one paying for the transportation service. Requires motor carriers to disclose actual rates, charges, or allowances for such transportation service. Prohibits persons from causing a motor carrier to present false or misleading information with respect to such rates, charges, or allowances. Sets forth civil penalties for knowingly paying, accepting, or soliciting reduced rates in violation of regulations. (Sec. 8) Grants the ICC jurisdiction to resolve disputes arising with respect to certain motor carriers as to whether transportation is provided as a motor common carrier or as a motor contract carrier. Declares that nothing in this Act shall be construed as limiting U.S. bankruptcy laws, including the jurisdiction of bankruptcy courts, or the applicability of the Employee Retirement Income Security Act of 1974, with respect to bankrupt carriers.