Upcoming National Meeting 57th Annual Meeting The Annual Meeting offers sessions for every state tax and government affairs professional with tax responsibilities. The Meeting has an extensive program covering all types of state and local taxes that business taxpayers are confronted with on a daily basis. The ever-popular audit sessions and state chamber of commerce roundtables are included, and other conference sessions provide updates on
Legislative Alert ISSUE 26-24; June 17, 2026 COST Provides Comments on Proposed Amendments to Illinois Addback Regulation; COST Supports Michigan Marketplace Facilitator Legislation
Cost Conscious ISSUE 26-12; June 12, 2026 Washington State Margins Tax Proposal – Member Feedback – Washington State Representative April Berg (D) circulated draft legislation that would replace Washington’s B&O tax with a Texas-style margins tax, phased in over five years beginning in 2028. The proposal would apply to all entity types with substantial nexus under current standards and would introduce mandatory unitary combined reporting.
COST - Council on State Taxation Amicus Briefs AT&T Mobility, LLC v. Board of Supervisors of Lamar County, Mississippi COST filed an amicus brief requesting the Supreme Court of Mississippi to accept an interlocutory appeal to address both the legality of, and constitutional issues with, a county assessor’s property tax valuation of a telecommunications company’s personal property. The brief pointed out concerns with the assessor not following the State’s valuation process which for industrial personal property is
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 Comments Re: Amendments to 86 Ill. Adm. Code 100.2430. COST submitted comments to the Illinois Department of Revenue on draft regulations 86 IL Admn.100.2430 addressing the deduction for interest and intangible expenses related to cross-border transactions.
