The constitutionality control of all the norms introduced in the system of brazilian positive law is ultimately conferred on the Supreme Federal Court (STF). The compatibility of the norms with the most appropriate interpretation of the Federal Constitution is an important means to assess their validity before the Brazilian order, hence the relevance of the role of the Court.
The Constitution is at the apex of the legal system, so that all the rules introduced in the system, so that they can be considered valid and, consequently, take effect, must keep strict compliance with the constitutional text. This is relevant because, on certain occasions, there may be a confrontation between principles and/or rules inserted in the Federal Constitution. In such cases, all the values involved and the protected legal object must be investigated in order to achieve a solution according to the Constitution, that is, the hierarchically higher value should be considered.
Strict compliance with the commands of the Constitution constitutes a measure of legal certainty, since it prescribes the essential rules of the order and any violation of its determinations constitutes serious offense to its fundamental bases. It is for no other reason that the rules that have vices before the Constitution are invalid. The declaration of unconstitutionality of a law has retroactive effect, as a rule, which, at least in the case, implies the withdrawal of all the consequences arising from its application from the legal world. In practice, after the declaration of unconstitutionality of the rule, the previous situation should be restored.
Although the recognition of the unconstitutionality of the law or rule departs from the effects of the conduct based on it (retroactive effect of the declaration of unconstitutionality), these effects have the presumption of constitutionality, provided that they are emanating from the competent body and according to the rite provided for. This means that, until the unconstitutionality of the law or the normative act is declared by the competent body, its effects must be observed.
It can be affirmed that the control of constitutionality of laws and norms is, in fact, the investigation of their compatibility and validity before the system in which it was inserted. The reference for this evaluation is the constitutional text and the interpretation given by the Supreme Court in force when a new rule is introduced into the system.
The so-called supervening constitutionality is not admitted in the Brazilian order. This would occur if an introduced rule did not find a basis for validity in the constitutional text in force at the time of its introduction into the system, but, due to a modification of the Federal Constitution or even a law of higher hierarchy (complementary law, for example), had its compatibility attested later, as if the defect inherent in the legislative diploma at the time of its edition could be corrected.
The Supreme Court has already had the opportunity to address the issue in some opportunities and we will pay special attention to some cases involving tax matters.
At the judgment of Extraordinary Appeal 390,840, the Supreme Court analyzed the constitutionality of Article 3, § 1, of Law 9.718/98, which altered the basis for calculating contributions to PIS and Cofins.
Law 9,718 was published on November 28, 1998, at which time Article 195, item I of the Federal Constitution, authorized the creation of a social contribution on the billing of the legal entity. At that time, it was understood that billing comprised the revenues inferred by the legal entity as a result of the sale of goods or the provision of services.
However, the amendment promoted by Article 3, §1, of Law 9.718/98, provided that, for the purposes of the calculation of the PIS and Cofins, the billing would comprise the gross revenue of the legal entity, understood as the total revenues. With this, there was the expansion of the calculation base of the PIS and Cofins, without the constitutional text having authorized the creation of contribution on revenue.
Before the effects of Article 3, §1, of Law 9,718/98 began, in February 1999, constitutional amendment 20 of December 15, 1998 was promulgated, which modified the wording of item I of Article 195 of the Federal Constitution, adding that a social contribution could also be instituted on the revenue of the legal entity.
In assessing Extraordinary Appeal 390,840, the Supreme Court ruled that Article 3, §1, of Law 9,718/98 was unconstitutional, since, at the time of its publication, which marks its introduction into the system, the Federal Constitution did not authorize the incidence of social contribution on the revenue of the legal entity. Moreover, the fact that Constitutional Amendment 20/98 was promulgated before the beginning of the production of the effects of the device does not affect the examination of constitutionality, which returns to the instant of the entry of the norm into the system. Therefore, the Supreme Court was precise in stating that "the Brazilian legal system does not contemplate the figure of supervening constitutionality".
It should be added that, at the judgment of Extraordinary Appeal 1,221,330, the constitutionality of state law was debated issued after the promulgation of Constitutional Amendment 33 of December 11, 2001. This constitutional amendment included among the hypotheses of incidence of ICMS the importation of goods by a non-taxpayer of the tax.
However, before Complementary Law 114 of December 2002, which amended Complementary Law 87/96 and added this new hypothesis of incidence of ICMS, some states modified their domestic legislation. Thus, the core of the discussion was: the state law edited on the basis of the constitutional amendment, but before the amendment of the complementary law, is it constitutional?
The Supreme Court prevailed the understanding that state laws are constitutional, since the constitutional text, with the modifications of constitutional amendment 33/01, authorized the incidence of ICMS on the import of goods by non-taxpayer. However, in view of Article 155, § 2, item XII, point 'a', of the Federal Constitutional, which requires complementary law to define the taxpayer of the tax, only after the entry into force of Complementary Law 114/02 would state laws take effect.
In this case, the Supreme Court adopted an intermediate position on the supervening constitutionality with which we do not agree. The premise that the new law should be in line with the provisions of the Federal Constitution at the time of its introduction into the system was maintained, in the part concerning the hypothesis of incidence of the ICMS. However, the requirement of supplementary law was made more flexible so that the states of the federation could modify their domestic legislation.
In other words, the Supreme Court ruled that the condition of Article 155, § 2, item XII, point 'a', which provides that the supplementary law will define the taxpayer of the ICMS, would be a requirement of effectiveness (to allow the production of effects) of state laws. Therefore, it is concluded by the constitutionality of state laws, which would only take effect after the edition of Complementary Law 114/02.
Our disagreement concerns the flexibility adopted by the Supreme Court regarding the fulfillment of all constitutional commandments that deal with the matter. For the states to institute the ICMS in their territories, the hypotheses provided for in the Federal Constitution must be observed and, likewise, the complementary law that will deal with the topics listed in the fundamental text itself. That is, for this analysis, the constitutionality of a state law is conditional on meeting both requirements. If anyone has been complied with, state law will be flawed and therefore should be declared unconstitutional.
These are cumulative requirements for the measurement of the constitutionality of the law, and it is inappropriate to consider the requirement of complementary law as a condition for state laws to begin to take effect.
The theme of the possibility of supervenient constitutionality should be reconsidered by the Supreme Court in the judgment of Extraordinary Appeal 592.152. The discussion, in this case, is about the constitutionality of state laws that instituted State Funds to Combat Poverty, financed with an additional iCMS rate, without compliance with Article 82 of the Transitional Constitutional Provisions Act, with the drafting of constitutional amendment 31/00, but which came to be validated by Article 4 of Constitutional Amendment 42/03.
Considerations on the subject should also be made taking into account the recent Supplementary Law 190, published on 5 January 2022.
At the judgment of Extraordinary Appeal 1,287,019, theme 1,093 of the general repercussion, the Supreme Court ruled that the requirement of the iCMS rate differential in the sale of goods to non-taxpayer final consumer of the tax located in a state other than the sender, since, at the time of the trial, complementary law had not yet been issued. Constitutional Amendment 87/15 modified Article 155 of the Federal Constitution and established that, in interstate operations with non-taxpayer final consumer of ICMS, the state of destination could charge the tax rate differential. Until then, the rate differential could be charged only in interstate operation with tax taxpayer.
However, before the issue of supplementary law to amend the text of Complementary Law 87/96, many states introduced state laws with the collection of the ICMS rate differential in interstate operations with non-taxpayers.
In the judgment in Extraordinary Appeal 1.287.019, the Supreme Court recognized the unconstitutionality of the collection of the rate differential until a supplementary law is created to dispose of this requirement. In order to prevent the determination of numerous actions with a request to repeat the values collected up to that moment, there was the modulation of the effects of the decision in that part, so that the orientation would take effect from 2022. The decision was delivered on 24 February 2021 and published on 25 May 2021.
In line with the Supreme Court's decision, the expectation was that a complementary law would be edited and published in 2021, so that, from 2022, the rate differential in interstate operations with non-taxpayer iCMS could be validly demanded by the states, after the modification of their respective internal laws.
That's not what happened. Only on January 5, 2022 was the publication of Complementary Law 190, which reproduced the new hypothesis for charging the ICMS rate differential in interstate operations with non-taxpayer. As for the production of effects, Article 3 of Complementary Law 190/22 provides that Article 150( III, paragraph 'c', of the Federal Constitution (principles of general and nonagesimal precedement) must be observed.
All these circumstances lead to the conclusion that Complementary Law 190/22 will take effect from January 1, 2023. In addition, the state laws that provide for the requirement of the ICMS rate differential in interstate operations with non-taxpayers issued before the publication of the complementary law contain the vice of unconstitutionality, which is why, in order for states to collect the tax, they must create new norms, since, as demonstrated, the supervening constitutionality is not admitted in Brazil.
It is concluded, therefore, that the so-called supervening constitutionality is not supported by the Brazilian order, and the jurisprudence of the Supreme Court confirms this position. The measurement of the constitutionality of a new law should be made on the basis of the constitutional text in force at the time of its introduction, so that any subsequent modifications do not have the power to correct an existing defect in the norm since its creation.
 This function is also performed by all members of the Judiciary, but in this text we will focus on the performance of the Supreme Court.
 RE 390840, rapporteur min. Marco Aurélio, Tribunal Pleno, tried on 09/11/2005, DJ 15/08/2006.
 RE 1,221,330, Rapporteur Min. Luiz Fux, Rapporteur for Judgment Min. Alexandre De Moraes, Full Court, tried on 16/06/2020, DJ 17/08/2020.
 In this case, the discussion was related to the Law of the State of São Paulo, number 11.001/2001. However, considering the national character of the ICMS and requirement by all States of the Federation, the rational is applicable for all.
 The rapporteur is the min. Ricardo Lewandowski.
 RE 1287019, rapporteur min. Marcus Aurelius, rapporteur for min judgment. Dias Toffoli, Full Court, tried on 02/24/2021, DJ 25/05/2021.