1. Nexus and Economic Presence: State and Local Tax Jurisdiction Standards
State taxing authority over a business depends entirely on the existence of a sufficient connection, or nexus, between the company and the state. Physical presence once defined the outer limit of state tax jurisdiction, but economic nexus standards have dramatically expanded that reach. State and local tax counsel must evaluate nexus exposure in every jurisdiction where a business generates revenue, regardless of physical presence.
What Businesses Must Know about Economic Nexus after the Wayfair Decision
The Supreme Court's 2018 decision in South Dakota v. Wayfair eliminated the physical presence requirement for sales tax collection, allowing states to impose collection obligations based solely on economic activity. Most states have enacted economic nexus thresholds, triggered when a seller reaches one hundred thousand dollars in annual sales or two hundred transactions. State and local tax counsel must monitor each jurisdiction's thresholds continuously, as states revise their standards without advance notice.
Sales Tax Collection for Out-of-State Sellers: Scope and Exemptions
Out-of-state sellers that establish economic nexus must register, collect, and remit sales tax in each triggering state without delay. Failure to register promptly exposes sellers to back taxes, interest, and significant penalties for each period of non-compliance. State and local tax counsel auditing e-commerce sales compliance must verify that exemption documentation satisfies each state's distinct format and retention requirements.
2. Multi-State Tax Apportionment and the Unitary Business Principle
Multi-state tax apportionment determines what share of a company's total income is subject to each state's income tax. Apportionment formulas differ by state, and the growing adoption of single sales factor weighting significantly affects companies with concentrated payroll or property in high-tax states. State and local tax planning must account for apportionment differences to minimize double taxation and identify refund opportunities across the company's active jurisdictions.
Apportionment Formulas and Single Sales Factor Trends in State Income Tax
Traditional apportionment used a three-factor formula weighting property, payroll, and sales equally to allocate income among states. Most states have now shifted toward single sales factor apportionment, assigning all weight to the ratio of in-state sales to total sales. Business tax counsel advising on apportionment strategies can identify filing positions that reduce aggregate state tax liability without increasing audit risk.
Unitary Business Principle: Defending against Combined Reporting Requirements
The unitary business principle authorizes states to require a group of commonly controlled entities to file a combined return, treating them as a single taxable unit. The legal test for unity focuses on functional integration, centralized management, and economies of scale among the affiliated entities. Taxpayers defending against combined reporting must document the operational independence, separate management, and distinct markets of each affiliated entity. State and local tax laws counsel challenging a combined reporting assessment must build a factual record that distinguishes legitimate separate operations from income-shifting arrangements.
3. Sales and Use Tax on Digital Services and Marketplace Facilitators
The taxation of digital products and services remains one of the most contested and rapidly evolving areas of state and local tax law. States disagree sharply on whether SaaS subscriptions, cloud-based platforms, and digital downloads constitute taxable tangible personal property or nontaxable services. State and local tax counsel advising technology companies must monitor each state's digital services tax rules, which change frequently and without federal coordination.
How Do States Tax Saas and Cloud-Based Digital Services?
No federal framework governs the state and local tax treatment of software as a service, leaving businesses to navigate fifty different state regimes independently. Some states classify SaaS as taxable tangible personal property delivered electronically, while others treat it as a nontaxable service. Cloud computing arrangements raise distinct sourcing questions because the server, the operator, and the end user may each be located in different states. State and local tax counsel advising on digital services taxation must analyze both the characterization and sourcing of each revenue stream in each active state.
Marketplace Facilitator Tax Obligations and Platform Compliance
Marketplace facilitator laws, enacted by most states following the Wayfair decision, shift sales tax collection responsibility from individual sellers to the platforms on which they sell. Under these laws, major e-commerce platforms must collect, remit, and report sales tax on behalf of third-party sellers operating through their systems. Third-party sellers using marketplace platforms should confirm in writing that the platform is assuming full collection and remittance responsibility for all covered transactions. State and local tax counsel reviewing marketplace agreements must confirm that the contractual allocation of tax responsibility matches each state's legal framework.
4. State Tax Audit Defense and Voluntary Disclosure Agreements
State tax audits present significant financial risk, particularly for companies with multi-state operations that have not consistently registered and filed in every nexus jurisdiction. Voluntary disclosure agreements offer businesses a structured path to resolve past tax exposure with reduced penalties and a limited lookback period. State and local tax counsel must evaluate whether VDA participation is preferable to non-compliance or contesting an audit assessment.
Vda Programs: Resolving Prior State and Local Tax Exposure Strategically
Voluntary disclosure agreements allow businesses with unregistered prior tax obligations to come forward, pay past-due tax, and receive penalty abatement in exchange for prompt compliance. Most states limit the VDA lookback period to three to four years, providing significant relief for companies with longer periods of undetected non-compliance. The timing of VDA participation is critical, since states typically deny amnesty to businesses that have already been contacted by the tax authority. State and local tax counsel must evaluate the exposure in each jurisdiction before selecting the sales tax arrears or voluntary disclosure pathway most favorable to the client.
State Tax Audit Defense, Refund Claims, and Administrative Appeals
Audit defense requires counsel to manage document production, challenge the auditor's legal interpretations, and preserve factual arguments for administrative appeal. Businesses that overpaid state taxes due to an incorrect legal position or changed tax law may file a refund claim through tax audits and adjustments procedures to recover the overpayment. Corporate tax refund and recovery actions add accrued interest to the refund amount, making prompt filing essential to maximizing total recovery. State and local tax counsel who builds the administrative record carefully creates the foundation for a successful refund recovery or appellate reversal.
30 Oct, 2025
