COST membership is exclusive; only multistate businesses that are not engaged in tax advising or consulting may apply for corporate membership. Once a member of COST, a business will benefit from saving: taxes as a result of identifying tax saving opportunities; training money through participation in COST conferences and schools; professional staff time through participation in a national network of corporate state tax professionals sharing technical knowledge; and resources from being a direct and indirect beneficiary of the legislative actions and advocacy of COST.