Sales tax nexus is the connection between a tax jurisdiction (e.g., a state) and a business that enables the jurisdiction to tax the business’s sales. A company with nexus in California must register with the California Department of Tax and Fee Administration, collect and remit sales tax, and file returns as required by law. A company without nexus can’t be required to do so.
Nexus is established by having a physical presence in a state, such as a brick-and-mortar store, warehouse, or employees. In 43 states plus the District of Columbia and parts of Alaska, it can also be established solely through sales activity (economic nexus), meaning businesses with no physical presence in a state can be required to register then collect and remit sales tax in that state.
Most state economic nexus laws provide an exception for small sellers, but that’s a bit of a double-edged sword. In California, the economic nexus threshold is $500,000 in sales in the preceding or current calendar year. But it’s $100,000 in sales or 200 transactions in Illinois, and $500,000 in sales and 100 transactions in New York. Every state’s economic nexus threshold is unique and subject to change.
Consequently, businesses must track their sales into all states with economic nexus laws so they can register and start collecting sales tax once an economic nexus threshold has been met. That takes time, though this free sales tax risk assessment tool can help.