Uniformity, Internet Freedom to Dominate 2026 State Tax Cases

Significant litigation wins in 2025 are likely to embolden taxpayers to expand their use of certain challenges to state tax laws in the coming year.

Although arguments relying on state uniformity clauses and federal protections for internet commerce and doing business in other states aren’t new, they’re being used more frequently. And more challenges could be filed before states have a chance to enforce new regulations and statutes.

Here are three legal theories state and local tax practitioners can expect to see more of in the courts in 2026.

Uniformity Clauses

Visiting professional athletes and entertainers were successful this year ...