"[attribution needed] COST is a non-profit trade association based in Washington, D.C. consisting of approximately 550 multistate corporations engaged in interstate and international business.

[3] COST's objective is to preserve and promote equitable and nondiscriminatory state and local taxation of multijurisdictional business entities.

COST's advocacy program is oriented toward active involvement on state tax issues of broad importance to the membership.

COST disseminates information on pertinent legislative, judicial and regulatory developments through regular publications, and coordinates advocacy activities with members and other sympathetic parties.

COST files amicus briefs with state and federal courts, provides testimony (oral and written) before legislative and administrative bodies, meets regularly with state policymakers, and brings together interested members to enhance advocacy activities on targeted issues.