On October 21, 2013, the Commission filed its amicus curiae brief on the merits in support of California in Gillette v. California Franchise Tax Board now pending at the California Supreme Court. In the brief, the Commission argues that California law may vary from Compact Articles III.1 and IV because the Multistate Tax Compact is an advisory compact, and Articles III.1 and IV of the Compact are more in the nature of a model uniform law. Tellingly, the Multistate Tax Compact does not exhibit any indicia of a binding interstate compact — in contrast to the compacts Gillette relies on in making its case — because the Compact (1) does not establish a joint regulatory body, (2) does not require reciprocal action to be effective, and (3) does not prohibit unilateral modification or repeal.
Moreover, if the Compact is to be characterized as an interstate contract, California may vary from Articles III.1 and IV because the Compact itself may be and has been interpreted by its member states to allow for variations in the enactment of Articles III.1 and IV, and the member states course of performance during the 46 years that the Commission has been in existence shows that they have so interpreted the Compact.
You can read the Commission’s brief here.