It is of course true that the Act describes the payment asa “penalty,” not a “tax.” But while that label is fatal to the application of the Anti-Injunction Act, supra, at 12–13, it does not determine whether the payment may be viewedas an exercise of Congress’s taxing power. It is up to Congress
whether to apply the Anti-Injunction Act to any particular statute, so it makes sense to be guided by Congress’s choice of label on that question.
That choice does not, however, control whether an exaction is within Congress’s constitutional power to tax.
Our precedent reflects this: In 1922, we decided two challenges to the “Child Labor Tax” on the same day. In the first, we held that a suit to enjoin collection of the so called tax was barred by the Anti-Injunction Act.
George, 259 U. S., at 20. Congress knew that suits to obstruct taxes had to await payment under the Anti-InjunctionAct; Congress called the child labor tax a tax; Congress therefore intended the Anti-Injunction Act to apply.
In the second case, however, we held that the same exaction, although labeled a tax, was not in fact authorized by Congress’s taxing power. Drexel Furniture, 259 U. S., at 38. That constitutional question was not controlled by Congress’s choice of label.
We have similarly held that exactions not labeled taxes nonetheless were authorized by Congress’s power to tax.
In the License Tax Cases, for example, we held that federal licenses to sell liquor and lottery tickets—for which the licensee had to pay a fee—could be sustained as exercises of the taxing power. 5 Wall., at 471. And in New York v. United States we upheld as a tax a “surcharge” on out-of-state nuclear waste shipments, a portion of which was paid to the Federal Treasury. 505 U. S., at 171. We thus ask whether the shared responsibility payment falls within Congress’s taxing power, “[d]isregarding the designation of the exaction, and viewing its substance and application.”
United States v. Constantine, 296 U. S. 287, 294 (1935); cf. Quill Corp. v. North Dakota, 504 U. S. 298, 310 (1992) (“[M]agic words or labels” should not “disable an otherwise constitutional levy” (
internal quotation marks omitted)); Nelson v. Sears, Roebuck & Co., 312 U. S. 359, 363 (1941) (“In passing on the constitutionality of a tax law, we are concerned only with its practical operation,not its definition or the precise form of descriptive words which may be applied to it”
(internal quotation marks omitted)) . . .