It is of course true that the Act describes the payment as a 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 viewed as an exercise of Congresss taxing power. It is up to Con-gress whether to apply the Anti-Injunction Act to any particular statute, so it makes sense to be guided by Con-gresss choice of label on that question. That choice does not, however, control whether an exaction is within Con-gresss constitutional power to tax.Our precedent reflects this: In 1922, we decided two
Opinion of R
OBERTS
,
C. J.
34 NATIONAL FEDERATION OF INDEPENDENT BUSINESS
v.
SEBELIUS
Opinion of the Court
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-Injunction Act; 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 Con-gresss taxing power.
Drexel Furniture
, 259 U. S., at 38.That constitutional question was not controlled by Con-gress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 waspaid 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 designa-tion of the exaction, and viewing its substance and appli-cation.
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 another wise constitutional levy (internal quotation marks omitted));
Nelson
v.
Sears
,
Roebuck & Co.
, 312 U. S. 359,363 (1941) (In passing on the constitutionality of a taxlaw, 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));
United States
v.
Sotelo
, 436 U. S. 268, 275(1978) (That the funds due are referred to as a penalty
Opinion of R
OBERTS
,
C. J.
35Cite as: 567 U. S. ____ (2012)Opinion of the Court
. . . does not alter their essential character as taxes

.
7
Our cases confirm this functional approach. For ex-ample, in
Drexel Furniture
, we focused on three practical characteristics of the so-called tax on employing child laborers that convinced us the tax was actually a pen-alty. First, the tax imposed an exceedingly heavy bur-den10 percent of a companys net incomeon those who employed children, no matter how small their infraction.Second, it imposed that exaction only on those who know-ingly employed underage laborers. Such scienter require-ments are typical of punitive statutes, because Congress often wishes to punish only those who intentionally break the law. Third, this tax was enforced in part by the Department of Labor, an agency responsible for pun-ishing violations of labor laws, not collecting revenue. 259U. S., at 3637; see also,
e.g., Kurth Ranch
, 511 U. S., at780782 (considering,
inter alia
, the amount of the exac-tion, and the fact that it was imposed for violation of a separate criminal law);
Constantine
,
supra
, at 295 (same).The same analysis here suggests that the shared re-sponsibility payment may for constitutional purposes be considered a tax, not a penalty: * * * *