What is sales tax nexus?

Sales tax nexus is the connection between a business and a state that creates an obligation to collect and remit sales tax, established through physical presence, economic activity, or other factors. For professional service firms, nexus determines whether services are subject to state sales tax requirements.

Key characteristics

• Connection creating tax obligation

• Varies by state rules

• Physical or economic presence

• Affects collection requirements

• Services are often exempt but vary

• Penalties for non-compliance

Why it matters for professional service firms

Nexus determines where you must collect sales tax. Ignoring nexus creates liability for uncollected taxes plus penalties. Professional service firms should understand nexus rules in states where they operate, recognizing that most professional services are exempt, but some states tax certain services.

Real-world example

Rachel's consulting firm served clients in 12 states. Nexus analysis: physical presence in 3 states, economic nexus threshold exceeded in 4 additional states. Service taxability review: professional services are exempt in most states, but one state taxes consulting services. Registered, collected, and remitted sales tax in that state. Avoided $18,000 potential liability from prior non-compliance.