Feature2026 COST Events...At A Glance October 6, 2025

Now is a great time to start planning your conference attendance for 2026!

Register before December 31st for discounted rates!

FeatureHollis Hyans Awarded for Excellence in State Taxation by COST September 17, 2025

The COST Board was pleased to announce at COST’s 56th Annual Meeting in Memphis, Tennessee that Hollis Hyans is the recipient of the 2025 COST/Paul Frankel Excellence in State Taxation Award. 

FeatureTracking Chart: State and Local Disaster Relief Guidance October 3, 2025

COST is tracking state and local tax relief guidance in response to fires and other natural disasters.

FeatureRevisiting the Debate Over State Taxation Of Foreign-Source Income (Tax Notes State, June 23, 2025) June 23, 2025

In this article, COST’s Karl Frieden and Doug Lindholm analyze California’s proposed digital advertising tax (DAT), comparing it with the existing Maryland DAT, and provide their rebuttal to Darien Shanske’s and Young Ran (Christine) Kim’s flawed characterization of and justification for the California DAT legislation as a digital barter tax. This article is a follow up to Frieden and Lindholm’s article on “State Digital Services Taxes: A Bad Idea Under Any Theory” that appeared in Tax Notes State on April 10, 2023. 

FeatureThe Mobile Workforce Act Introduced in the U.S. Senate April 10, 2025

Senate Majority Leader John Thune (R-SD) and Senator Catherine Cortez Masto (D-NV) today announced their introduction of the Mobile Workforce State Income Tax Simplification Act of 2025, S. 1443, which would set a uniform 30-day threshold before employees who travel across state borders for work become subject to personal income tax filing in nonresident states, and their employers on corresponding withholding obligations. For over a decade, COST and over 300 other organizations and businesses led efforts in the Congress towards enactment of the Mobile Workforce Act and since 2019, COST has simultaneously been engaged in state-by-state efforts to combat the patchwork of state laws governing the taxation of nonresident traveling workers.

FeatureThe Boomerang Effect of the Business ‘Fair Share’ Tax Debate (Tax Notes State, February 10, 2025) February 10, 2025

In this article, COST’s Karl Frieden and Doug Lindholm analyze California’s proposed digital advertising tax (DAT), comparing it with the existing Maryland DAT, and provide their rebuttal to Darien Shanske’s and Young Ran (Christine) Kim’s flawed characterization of and justification for the California DAT legislation as a digital barter tax. This article is a follow up to Frieden and Lindholm’s article on “State Digital Services Taxes: A Bad Idea Under Any Theory” that appeared in Tax Notes State on April 10, 2023. 

Feature2024 State and Local Business Tax Burden Study December 20, 2024

The Council On State Taxation (COST) and the State Tax Research Institute (STRI) are pleased to announce the release of the 22^nd annual study of state and local business taxes. The report, “Total State and Local Business Taxes: State-by-State Estimates for Fiscal Year 2023,” prepared by Ernst & Young LLP, shows all state and local business taxes paid in each of the 50 states and the District of Columbia. 

Businesses paid $1,096.2 billion in state and local taxes in FY2023, an increase of 3.7% from FY2022. State business taxes increased by 0.9%, and local business taxes grew by 7.3%. In FY2023, business tax revenue accounted for 44.7% of all state and local tax revenue.