Business changes, including growth, new products and services, expanding sales channels, and mergers or acquisitions can significantly alter an organization’s sales tax obligations. While economic nexus often receives the greatest attention, it represents only one component of the overall analysis. Physical presence, product taxability, jurisdiction-specific rules, business documentation, and internal compliance processes all influence how organizations establish and support their sales tax positions.

A change in where or how a business operates, what it sells, or how it documents its products and services may affect filing obligations, tax treatment, and compliance requirements across multiple jurisdictions. Evaluating these areas together can help organizations identify potential exposure earlier, support more consistent tax positions, be better prepared for state and local sales tax audits, and respond effectively as state and local sales tax rules continue to change.

Economic nexus determines where sales tax obligations begin

Economic nexus establishes where an organization may have sales tax registration and filing obligations. Since the Wayfair decision, businesses can create nexus through economic activity alone, even without a physical presence in a state. As organizations expand into new markets or sales channels, evaluating where nexus exists is often the first step in determining their sales tax responsibilities.

Economic nexus thresholds vary by jurisdiction. While many states apply a $100,000 sales threshold, others include transaction thresholds or establish different requirements altogether. For example, New York requires both $500,000 in sales and 100 transactions before economic nexus is established. These differences require organizations to evaluate nexus based on each state’s rules rather than rely on a single national standard. It is also important to keep in mind that economic nexus did not replace physical presence in a state. Thus, a Company may have less than $100,000 sales in a state but have employees working remotely from that state.

Marketplace facilitator rules add another layer of complexity. Although marketplace facilitators generally collect and remit sales tax on marketplace transactions, states differ on whether those sales count toward a seller’s economic nexus thresholds. Some exclude marketplace sales from the calculation, while others require organizations to combine marketplace and direct sales when evaluating nexus.

Because nexus rules continue to vary by jurisdiction, organizations should review their sales activity and marketplace relationships quarterly or semi-annually to identify new registration and filing obligations as business operations evolve.

Product classification drives taxability

After determining where sales tax nexus and thus filing obligations exist, organizations must classify the products and services they sell. Product classification provides the foundation for determining taxability because states often apply different rules to tangible personal property, services, and digital products.

Products and services generally fall into one of the following categories:

• • Tangible personal property (TPP). Physical goods are generally subject to sales tax, although exemptions (e.g., clothing) and special rules vary by jurisdiction.
  • Services. Professional, consulting, and management services are often not taxable unless specifically identified by a state’s tax code. Construction services, real property improvements, and tangible personal property installation services frequently require additional jurisdiction-specific analysis.
  • Digital products and software. States continue to take different approaches to software, digital goods, electronically delivered products, and software as a service (SaaS), making product classification increasingly important as digital offerings expand.

Accurate product classification allows organizations to evaluate jurisdiction-specific taxability with greater consistency as they expand across multiple states.

Jurisdiction-specific tax rules require ongoing review

As noted above, establishing nexus is only the first step in the sales tax process. Organizations must also determine how each product or service is taxed in every jurisdiction where they do business. States and localities continue to take different approaches to software, digital products, and services, while legislative changes and administrative guidance can further affect tax treatment over time.

Examples include:

• • Florida generally does not tax electronically delivered products, including SaaS, while New York broadly taxes electronic products and software.
  • Illinois does not tax SaaS at the state level, but Chicago's lease transaction tax applies to SaaS within the city.
  • Colorado recently expanded the taxation of digital products and software whereas Denver has historically imposed sales tax on SaaS. Colorado also introduced an exemption for qualifying software sold under negotiated license agreements. Additional guidance is expected to clarify how that State exemption will be applied.
  • California will begin taxing certain digital goods, software, and SaaS beginning Jan. 1, 2027. The legislation (Opens a new window) represents a significant change for organizations that develop or sell digital products, and additional guidance is expected before the law takes effect.

As states continue to revise the tax treatment of software, digital products, and services, taxability determinations cannot be treated as static. Ongoing monitoring of product classifications, legislative developments, and jurisdiction-specific requirements help organizations maintain consistent sales tax treatment as state rules evolve.

Once organizations determine how products and services should be taxed, the focus shifts from establishing sales tax positions to supporting and maintaining them. Documentation, historical compliance, and ongoing internal reviews all play an important role in sustaining those positions over time.

Consistent business documentation strengthens sales tax positions

Determining the appropriate sales tax treatment is only part of the process. During an audit, taxing authorities may review contracts, statements of work, websites, exemption certificates, and other business records to evaluate how products and services are represented and whether that documentation supports the organization’s sales tax treatment.

Areas that commonly warrant regular reassessment include:

• • Contracts and statements of work that describe the products and services provided to customers.
  • Website content and marketing materials that explain how products and services are offered in the marketplace.
  • Exemption certificates and supporting documentation for transactions treated as exempt.
  • Negotiated license agreements that may affect the tax treatment of software in jurisdictions with statutory exemptions.

Consistent documentation can strengthen support for sales tax positions, reduce uncertainty during audits, and help identify inconsistencies before they affect significant business transactions.

Evaluate historical exposure before it becomes an audit issue

Organizations that identify historical sales tax exposure may have options to resolve those liabilities before an audit occurs. Voluntary disclosure agreements (VDAs) allow businesses to voluntarily register with a state and address prior-period obligations under terms that may include a limited lookback period, penalty abatement, and, in some jurisdictions, reduced interest. Like taxability and nexus rules, it is critical to review whether the business even qualifies for a VDA.

Prospective registration alone does not resolve historical exposure. Statute of limitations protections generally begin only after a business registers and files returns, leaving earlier periods potentially subject to review when nexus existed, but filing obligations were not met.

Periodically evaluating historical exposure and available remediation options allow organizations to resolve outstanding obligations while reducing uncertainty associated with future audits.

Internal controls help sustain sales tax compliance

Registration and filing returns are only part of maintaining sales tax compliance. Continuing evaluation of accounting records, purchasing activities, and supporting documentation helps organizations identify reporting discrepancies before they become audit issues. Companies should also consult with their trusted advisors to help ensure appropriate records and documentation are maintained to support compliance positions and withstand scrutiny during an audit.

Assess your business regularly

Sales tax obligations rarely change because of tax law alone. More often, sales tax obligations expand because the business itself changes its footprint in a state due to a new physical or revenue based nexus Periodically evaluating these business changes alongside nexus, product classification, jurisdiction-specific taxability, and supporting documentation supports organizations to identify potential exposure earlier, strengthen compliance processes, and make more informed decisions as their operations continue to evolve.

For a deeper dive, watch our webinar Sales tax nexus & product taxability: Risks & compliance (Opens a new window).