The defendant there was a consignee to whom goods had been delivered under bills of lading marked "prepaid." Relying upon the carrier's explicit representation of prepayment, the consignee paid the amount of the freight charges to the shipper-consignor. In fact, however, the carrier had extended credit to the consignor and had failed to collect the charges within the period allowed by the regulations. When the consignor went out of business, the carrier turned to the consignee for payment. The Court of Appeals, by a divided vote, held the carrier estopped.

Admiral differs from this case in four crucial respects. First, in Admiral, the carrier not only violated ICC credit regulations but also made to the defendant a material misrepresentation regarding prepayment. The carrier here, in contrast, was charged solely with failure to observe the applicable ICC credit regulations. Second, in the Seventh Circuit case, the consignee-defendant had paid full freight charges to the consignor. Had the Seventh Circuit also awarded relief to the carrier, it would have "require[d] an innocent consignee to defray freight charges exactly double the amount contemplated by the applicable tariffs." 442 F. 2d, at 65 (Stevens, J., concurring). Here, the defendant paid no freight charges; thus, an award of relief to the carrier creates no possibility of enforcing a double payment.

Third, in Admiral, the grounds for equitable estoppel were created by the consignee's payment of freight charges in detrimental reliance on the carrier's misrepresentation. The carrier's violation of the credit regulations offered only "additional grounds for the intervention of the principles of equity." Id., at 60 (majority opinion). In this case, there is no suggestion that the consignor knew of, or changed its position detrimentally in reliance on, the carrier's credit violation. Fourth, and most significant, the defendant-consignee in the Seventh Circuit case had no means by which to protect itself from freight charge liability. In this case, of course, the defendant-consignor could have protected itself com

pletely simply by signing the nonrecourse clause in the bills of lading.

C. Finally, public policy concerns disfavor judicial implication of affirmative defenses based on carrier violations of the Commission's credit regulations. We recognize that the regulations are technical. Thousands of railcars are delivered every day by the country's railroads. See Association of American Railroads, Yearbook of Railroad Facts 25 (1981) (approximately 62,000 deliveries per day). Almost inevitably, some cars will be delivered to noncredit patrons, some freight bills will be sent out late, and some accounts will not be collected within the specified time. A 1966 study by the ICC's Bureau of Enforcement found that almost a third of 15,751 bills examined were overdue and that over half of those overdue were delinquent more than 10 days. See In re Regulations for Payment of Rates and Charges, 326 I. C. C. 483, 485 (1966). 10 After appraising this data, the ICC agreed that "the evidence establishes many and continued violations of the credit regulations. However, we are unable to conclude on this record that rigid rules. . . would provide a practical or desirable solution. [T]here are many reasons for credit violations which are beyond correction by rules, e. g., where shippers have unexpected peak workloads, where there are controversies over amounts due, where additional information is needed such as weights or evaluations, where standard office procedures are in the process of change, where temporary cash flow problems occur, and where it becomes necessary to check the validity of charges with third persons. Stringent credit rules. . . would destroy the flexibility needed to meet problems of this nature." Id., at 489-490. Indeed, in 1980, the ICC proposed repealing the credit regulations altogether, noting that "apparent, wide

10 The methodology of this study was questioned by the railroads. The roads' own figures, however, showed that of 445,984 collectible items accrued during the period of the investigation, more than 10,000 resulted in credit violations. 326 I. C. C., at 486.

spread noncompliance with the regulations indicates that the payment periods and other time limits prescribed are simply not realistic for many of the situations in which they apply." Ex parte Nos. MC-1, 73, 143, and 170, 45 Fed. Reg. 31766.

It thus appears that the Court of Appeals in the present case implied an affirmative defense that would penalize railroads for violations of the credit regulations just as the agency responsible for administering those regulations was pronouncing them unrealistic. The prospect raised for the carrier is that it will be barred from recovering lawful freight charges, even from a consignor who fails to execute the nonrecourse clause, for possibly unavoidable violations of the credit rules. "The obvious consequence would be to discourage [carriers] from extending credit where the operation of this rather difficult statute is in doubt." Bruce's Juices, Inc. v. American Can Co., 330 U. S. 743, 753 (1947). Ironically, those shippers who pay their bills currently in a responsible manner would suffer as a result.

Metals argues that a ruling for SP places SP "in the unrealistic position of being incapable of doing any wrong" and therefore creates "no incentive [for carriers] to improve inefficient and careless credit practices." Brief for Respondent 12.

Metals further claims that the loss at issue here would not have occurred if SP only had complied with its obligations under the regulations. Id., at 24. The answer to this is that the ICC has ample authority to police the credit practices of carriers and thereby to deter improper practices. This authority includes the power to issue a cease-and-desist order, see Shaw Warehouse Co. v. Southern R. Co., 308 I. C. C. 609, 633-634, 637 (1959), appeal dism'd sub nom. Southern R. Co. v. United States, 186 F. Supp. 29 (ND Ala. 1960); the power to seek a federal-court injunction requiring a carrier to comply with the regulations, see ICC v. AllAmerican, Inc., 505 F. 2d 1360 (CA7 1974); and the power to bring suit for the $5,000 civil forfeiture, provided by 49 U. S. C. § 16(8) and 49 U. S. C. §11901(a) (1976 ed., Supp.

III), for each knowing violation of an order of the Commission, see, e. g., United States v. Western Pacific R. Co., 385 F.2d 161 (CA10 1967), cert. denied sub nom. Denver & R. G. W. R. Co. v. United States, 391 U. S. 919 (1968); United States v. Pennsylvania R. Co., 308 F. Supp. 293 (ED Pa. 1969).

Thus, the ICC may regulate the credit practices of carriers even without the judicially created remedy of forfeiture of freight charges. Furthermore, a reading of the cited cases reveals that the question whether a credit violation has occurred often will require the ICC or the courts to conduct a factual inquiry as to the carrier's intent to violate the regulations. The "credit violation defense" adopted by the Court of Appeals requires a carrier to forfeit freight charges without regard to the nature of its violation." This inflexible ap

"The facts of this case illustrate the problems that may arise when a court ventures to create law in this highly technical field. The rulings of the District Court and the Court of Appeals denied SP recovery not only for the first car, which was delivered without any payment upon the freight charge, but also for the two cars for which it did demand payment before delivery and received checks for the charges.

Yet acceptance of a proper check as payment for a freight charge is an acknowledged commercial practice in the railroad industry. See Fullerton Lumber Co. v. Chicago, M., St. P. & P. R. Co., 282 U. S. 520, 522 (1931); see also 49 CFR § 1320.13 (1981). It therefore is at least possible that SP's insistence on payment by check before releasing the second and third cars constituted compliance with the regulations, which require only that the railroad take “precautions deemed by it to be sufficient to assure payment of the tariff charges." 49 CFR § 1320.1 (1981). It is true, of course, that the check for one car was understated by $900, but, as has been noted, SP mailed a freight bill for the correct amount to Carco within four days of the delivery. See 49 CFR § 1320.5 (1981) (carrier may extend credit for up to 30 days on balance due in the event of undercharges).

Furthermore, it is by no means clear that SP could safely have deferred delivery of the second and third cars until after Carco had paid the charges on the first car. The carrier's lien for unpaid charges covers only the goods in the immediate shipment. 49 U. S. C. § 105. See Atlas S.S. Co. v. Colombian Land Co., 102 F. 358, 361 (CA2 1900). Once Carco offered to pay the charges on the second and third cars, even serious suspicion

proach disenables courts from considering the carrier's intent, the degree of the shipper's fault, the effect of enforcement on the carrier's existing permissible credit practices, and other subjective factors in deciding whether or not to enforce a shipper's primary liability for freight charges.

Metals also advances a number of "double payment" cases in support of its claim for an affirmative defense. See, e. g., Southern Pacific Transp. Co. v. Campbell Soup Co., 455 F. 2d 1219 (CA8 1972); Consolidated Freightways Corp. v. Admiral Corp., 442 F. 2d 56 (CA7 1971); Farrell Lines, Inc. v. Titan Industrial Corp., 306 F. Supp. 1348 (SDNY), aff'd, 419 F.2d 835 (CA2 1969), cert. denied, 397 U. S. 1042 (1970); Southern Pacific Co. v. Valley Frosted Foods Co., 178 Pa. Super. 217, 116 A. 2d 70 (1955). To be sure, these cases speak in equity terms. But none of these cases turned solely on a carrier's violation of credit regulations. Each and all of them involved a carrier's misrepresentation, such as a false assertion of prepayment on the bill of lading, upon which a consignee detrimentally relied only to find itself later sued by the carrier for the same freight charges. We find that these double payment cases constitute their own category and stand against the placement of duplication of liability upon an innocent party. See Consolidated Freightways Corp. v. Admiral Corp., 442 F. 2d, at 65 (Stevens, J., concurring).

As we have noted above, no similar double payment liability is in prospect here. Metals, not the carrier, selected the consignee. Furthermore, Metals has been paid for its goods while the carrier has not been paid for its services. The carrier unsuccessfully has pursued its remedies against the consignee before turning to the shipper-consignor for payment. Nor had the statute of limitation run when SP finally sued Metals for payment.

about Carco's financial health might not have allowed SP to withhold delivery without risking liability to Carco for conversion of its goods. See 49 U. S. C. § 88 (carrier's duty to deliver goods on demand).