COST - Council on State Taxation Amicus Briefs Microsoft Corporation v. Oregon Department of Revenue The Microsoft v. Oregon DOR case raises the issue of fair apportionment. Specifically, whether the apportionment formula must be adjusted to reflect the foreign source income that was included in the tax base.
COST - Council on State Taxation COST Studies, Articles & Reports 2026 State and Local Amnesty Programs Tracker of most state and local tax amnesty programs enacted and conducted in 2026.
COST - Council on State Taxation COST Comments & Testimony Joint Letter re. Proposed Rules Implementing the Digital Asset Tax Act On October 30, 2026, COST signed onto a joint letter with the Taxpayers’ Federation of Illinois and the Illinois Bankers Association, submitted to the Illinois Department of Revenue in response to its proposed rules implementing the Illinois Digital Asset Tax Act.
