The Federal Supreme Court, when judging Extraordinary Appeal No. 593849, under the general repercussion system, decided that the states must return to the taxpayers the ICMS-ST difference existing when the effective tax base is lower than the presumed one. It also established that those who have already filed a lawsuit on the matter are entitled to the refund for the last five years, but those who have no lawsuit in progress can only claim the refund as of October 2016.
Regarding this issue, the Special Organ of the São Paulo Court of Justice, when considering the Argument of Unconstitutionality No. 0033098-49.2018.8.26.0000, recognized that São Paulo taxpayers are not subject to this deadline even if they have not yet filed a lawsuit, since article 66-B, II, paragraph 3, of Law 6,374/1989 already allowed the refund of overpaid ICMS-ST before the aforementioned Supreme Court decision was issued.
It is worth noting that the Special Body has ruled out CAT Communication No. 14/2018, issued by the Coordinator of Tax Administration of the State of São Paulo, which establishes that for the refund of the ICMS paid in advance under the tax substitution regime, a request referring to a period after 10/19/2016 will be admitted.
Thus, São Paulo taxpayers, who did not file a lawsuit before the Supreme Court judgment to obtain recognition to recover over-collected ICMS-ST, are entitled to the refund of said tax over the last five years, so that they are not limited to asking only for what was unduly collected as of October 2016.