No. 46, 49th Cong., 1st Sess., 181, 188-190, 198-200 (1886). As the Commission itself found: “[P]ast experience shows that billing clerks and other agents of carriers might easily-become experts in the making of errors and mistakes in the quotation of rates to favored shippers, while other shippers, less fortunate in their relations with carriers and whose traffic is less important, would be compelled to pay the higher published rates.” Poor v. Chicago, B. & Q. R. Co., 12 I. C. C. 418, 421-422 (1907); see also Western Transp. Co. v. Wilson & Co., 682 F. 2d 1227, 1230-1231 (CA7 1982). Despite the harsh effects of the filed rate doctrine, we have consistently adhered to it. See, e. g., Thurston Motor Lines, Inc. v. Jordan K. Rand, Ltd., 460 U. S. 533, 535 (1983); Southern Pacific Transp. Co., 456 U. S., at 343-344; Baldwin v. Scott County Milling Co., 307 U. S. 478, 484-485 (1939); Louisville & Nashville R. Co. v. Central Iron & Coal Co., 265 U. S. 59, 65 (1924).
The filed rate doctrine, however, contains an important caveat: The filed rate is not enforceable if the ICC finds the rate to be unreasonable. See Maxwell, supra, at 97 (filed rate applies “unless it is found by the Commission to be ■unreasonable”) (emphasis added); see also Keogh, supra, at 163 (“The legal rights of shipper as against carrier in respect to a rate are measured by the published tariff. Unless and until suspended or set aside, this rate is made, for all purposes, the legal rate”) (emphasis added). The filed rate doctrine, therefore, follows from the requirement that only filed rates be collected, as commanded by §§ 10761 and 10762, the requirement that rates not be discriminatory, see § 10741, and the requirement of § 10701 that carriers adopt reasonable rates and practices. As we explained in Arizona Grocery, supra, although the filed rate is the legal rate, the Act
“did not abrogate, but [rather] expressly affirmed, the common-law duty to charge no more than a reasonable rate .... In other words, the legal rate was not made by the statute a lawful rate — it was lawful only if it was