Opinion by
Mr. Justice Cohen,Smith, Kline and French Laboratories manufactures and sells drugs, as defined by The Drug, Device and Cosmetic Act of September 26, 1961, P. L. 1664, §2(b), 35 P.S. §780-2(b) (Act) at two facilities located in Pennsylvania, including one within the limits of the City of Philadelphia. As required by Section 11 of the Act, Smith, Kline and French registered its manufacturing establishments in Pennsylvania in 1962 with the Secretary of Health of the Commonwealth and paid to *199the Commonwealth the statutory registration fees dictated by §11 (c) of the Act, viz., $100.00 for each manufacturing plant or a total of $200.00. Smith, Kline and French has continued to pay these registration fees annually thereafter.
For the years 1962 through 1965, inclusive, Smith, Kline and French filed Mercantile License Tax returns with the City of Philadelphia (City) and paid Mercantile License Taxes and fees to the City as follows:
Taxable Yecur
Amount of Tax and Fee Paid
1962 $24,032.44 (Tax)
1963 29,671.96 (Tax)
1964 3.00 (Fee)
33,522.30 (Tax)
1965 3.00 (Fee)
40,214.69 (Tax)
On January 5, 1966, Smith, Kline and French filed with the City Revenue Commissioner a refund claim for $127,450.39, being the total amount of Mercantile License Taxes and fees paid for the period 1962 to 1965. The basis of the refund claim was that the registration fees paid to the Commonwealth under the Act constituted true license fees, and consequently the City was prohibited from imposing its Mercantile License Tax under the Act of August 5, 1932, P. L. 45, as amended, §1, 53 P.S. §15971 (a), popularly known as the “Sterling Act.” This section, while granting first class cities broad authority to levy, assess and collect taxes, contains the following explicit exception: “. . . except that such council shall not have authority to levy, assess and collect . . . any tax on a privilege, transaction, subject or occupation, or on personal property, which is now or may hereafter become subject to a State tax or license fee.”
*200By letter dated March 23, 1966, the Revenue Commissioner denied the refund on the ground that the registration fees paid by Smith, Kline and French under the Act did not represent true license fees within the meaning of the Sterling Act. The Tax Review Board denied the appeal petition without opinion.1
On appeal to the Court of Common Pleas of Philadelphia County, the decision of the Tax Review Board was reversed. The lower court held that the registration fees paid by the drug manufacturer to the Commonwealth met all the criteria of true license fees and precluded the City from levying its Mercantile License Tax under the Sterling Act. Instead of ordering a refund, however, the lower court remanded the case to the Tax Review Board for the purpose of determining which of the activities, if any, of Smith, Kline and French fall outside the sphere of regulation under the Act and consequently became subject to the City’s Mercantile License Tax. The City of Philadelphia then brought this appeal under the Act of June 16, 1836, P. L. 784, §1, 17 P.S. §41.
In deciding this case, the answers to two questions must be found. First, what did the legislature mean when it (in an attempt to eliminate double taxation) exempted from local taxation activities “subject to a State . . . license fee?” Secondly, does The Drug, Device and Cosmetic Act impose the type of license fee the legislature referred to in the Sterling Act?
A number of cases have attempted to answer the first question: Philadelphia Coca-Cola Bottling Company v. Philadelphia, 382 Pa. 299, 115 A. 2d 207 (1955); Honorbilt Products, Inc. v. Philadelphia, 380 Pa. 630, 112 A. 2d 108 (1955); National Biscuit Co. v. *201Philadelphia, 374 Pa. 604, 98 A. 2d 182 (1953); Armour and Company v. Pittsburgh, 363 Pa. 109, 69 A. 2d 405 (1949) (this case and the one following construe the Act of June 25, 1947, P. L. 1145 rather than the Sterling Act, but both are relevant because the statutory wording and legislative purpose are identical); Pittsburgh Milk Company v. Pittsburgh, 360 Pa. 360, 62 A. 2d 49 (1948); Pennsylvania Liquor Control Board v. Publicker, 347 Pa. 555, 32 A. 2d 914 (1943); Freeman v. City of Philadelphia, 178 Pa. Superior Ct. 290, 116 A. 2d 349 (1955); Gunn Pontiac, Inc. v. Pittsburgh, 174 Pa. Superior Ct. 75, 99 A. 2d 404 (1953).
The approach of all the cited cases has been to see “license fee” as representing a regulatory statute enacted under the legislature’s police powers. Pa. Liq. Con. Bd. v. Publicker, supra at 560. The cases then aPPly the four criteria developed by this Court in National Biscuit, supra.
It appears to us that the cited decisions do not properly interpret the Sterling Act. In assuming that “license fee” can only refer to regulation under the Commonwealth’s police power, they ignore the possibility that “license fee” can refer to the raising of revenue under the Commonwealth’s taxing power. 33 Am. Jur. Licenses §2 (1941). Considering the legislature’s intent in 1932, the latter construction malíes the most sense. The Sterling Act is a permissive one; one that grants power to first class cities, and the reservation of power in the clause under consideration must be seen in the light of the legislative intent of providing sources of revenue for impoverished cities. Under the interpretation given in the cited decisions, the payment of $50 or $100 to the Commonwealth can deprive a city of many tens of thousands of dollars in tax revenue. Here appellee argues that its payment to the Commonwealth of $1000 over a five year period deprives Philadelphia of $164,170.27. It would certainly be anoma*202lous for the legislature to pass an act supposedly for the benefit of the cities and then take away much of what had been granted.
This problem was also recognized in National Biscuit, supra: “While it may seem, from a practical standpoint, that the payment of a mere license fee to the Commonwealth ought not to be regarded as sufficient to preclude the City from imposing a mercantile license tax on the State’s licensee, nevertheless the provision in the Sterling Act in that regard is explicit and unambiguous, and it is for the legislature alone to remove this limitation on the City’s power if that body should determine that such action is desirable.” 374 Pa. at 615.
There is no direct legislative history that the legislature meant “license fee” in a regulatory sense, and viewing it in a revenue sense does seem to best carry out what appears to have been the legislative intent.
It is the opinion of this Court that the power of cities under the Sterling Act is ousted only when the legislature has enacted a revenue-producing measure covering the same person, transaction, occupation, activity, privilege, subjects or personal property. Close questions will arise as to whether a particular enactment is a revenue-producing one, but it is not necessary to decide any such questions here. As a general rule, however, a revenue measure can be identified by (1) the large monetary income derived and (2) the large income compared to the costs of collection and supervision.
It is next necessary to determine into which category The Drug, Device and Cosmetic Act falls. It should be noted that appellant and appellee take the position opposite to that which they might have been expected to take. That, undoubtedly, is due to reliance on authorities this Court has now ruled are not controlling on the issue in question.
*203Because it does meet the four requirements laid down in National Biscuit, supra at 615 (which are still the test of a “regulatory” license fee) we find that The Drug, Device and Cosmetic Act is a regulatory measure passed under the Commonwealth’s police power; thus the City of Philadelphia is not barred by the Sterling Act. The Drug Act is clear in subjecting the industry to supervision and regulation by the licensing authority. Act of September 26, 1961, P. L. 1664, § §4, 11, 16, 17. Also, there seems no question that payment of the fee is a condition upon which the licensee is permitted to transact his business. Act, § §4, 11. The lower court found sufficient evidence that such supervision and regulation was actually conducted by the regulating agency. The Stipulation of Facts supports this finding adequately. Finally, leaving aside Dr. Maxwell’s testimony (as to whose admissibility appellant objected), the fact that the total fees collected from manufacturers and wholesalers throughout the period in question (4 years) so closely approximated the total expenses of supervision and regulation ($197,405 against $206,750.24), indicates that the legislative purpose in exacting the charge was to reimburse the licensing authority for the expenses of supervision and regulation. The same fact indicates that the Act was not designed as a revenue-producing measure and that the prohibition in the Sterling Act should not apply.
Judgment reversed.
Opinion by
Me. Justice Robebts:I could not agree more completely with the result reached in this case. I must note, however, that I do not feel it necessary to reach the difficult question of what is a “license fee,” for I would first compare the so-called “license fee” imposed by the Commonwealth with the tax imposed by the city. If they both fall on precisely the same “privilege, transaction, *204subject or occupation,” then, and only then, do we need reach the question of the proper definition of a “license fee.”
The purpose of the Sterling Act is to prohibit double-taxation, that is, to avoid a situation where two governmental units, the state and its political subdivision, are seeking revenue from a tax or license fee on the same base. We have never held, however, that merely because a business is taxed on a certain aspect of its operations by the Commonwealth, that it cannot therefore be taxed on a different aspect by the city. For example, in National Biscuit Co. v. Philadelphia, 374 Pa. 604, 98 A. 2d 182 (1953), we held that the payment of a state corporate income tax does not bar the city from imposing a mercantile tax which is based on the gross volume of business. Similarly, in Philadelphia v. Samuels, 338 Pa. 321, 12 A. 2d 79 (1940), we held that there was no conflict between the state corporate income tax and a parking lot tax based on gross receipts. Although in both cases we used the labels “property tax” and “excise tax” to distinguish the taxes involved, the distinction does not rest on labels. It rests on the different aspects of the business which are being taxed. The corporate income tax is a tax based on net income; the mercantile and parking lot taxes are taxes based on gross sales and receipts.
In the instant case the Commonwealth has placed a license fee of $100 on each of appellee’s two manufacturing plants. The city has placed a mercantile tax on appellee’s gross sales. It is even clearer here than in National Biscuit and Samuels, supra, that the two taxes fall on entirely different aspects of appellee’s business. This is not, in my view, the double-taxation which the Sterling Act forbids. A corporation may be required to pay different types of taxes based on different factors and items; the Sterling Act only forbids the city from taxing the same aspect of the business *205that the Commonwealth taxes. Since the license fee here is not based on gross sales, the city has the power to levy a tax on such sales. Accordingly, I concur in the result.
Mr. Justice Eagen joins in this opinion.By agreement with, the City, claimant amended its claim to include an additional $36,719.88 in Mercantile License Taxes paid for 1966.