Running an online business out of New York opens the door to nationwide customers—but also to a web of complex sales tax rules. Since the 2018 South Dakota v. Wayfair decision, states can require remote sellers to collect and remit sales tax based solely on economic activity within their borders—even if there’s no physical presence. That means a New York–based business can be on the hook for collecting sales tax in dozens of states, depending on where and how much it sells.

For small and midsize online businesses, especially those based in a high-compliance state like New York, it’s critical to stay ahead of your sales tax obligations. Failure to comply can result in back taxes, penalties, or even trigger an audit. This guide walks you through what you need to know: how nexus works, what triggers it, and how to manage multi-state compliance with confidence.

Understand Sales Tax Nexus In New York and Beyond

Nexus is the connection between your business and a state that requires you to collect and remit sales tax. There are several types of nexus, and you’ll need to track all of them carefully.

Economic nexus is the most common. Most states set a threshold—typically $100,000 in sales or 200 transactions per calendar year. Once you pass that, you’re required to register and collect sales tax.

But New York takes a slightly different approach. If your business sells more than $500,000 in tangible personal property and makes more than 100 separate transactions into the state annually, you’re considered to have economic nexus—even if you’re physically located outside of New York. For NYC-based businesses selling nationwide, this threshold could easily apply in reverse across multiple states as your sales grow.

There’s also physical nexus, which applies if you maintain an office, warehouse, or have employees in a state. Even remote employees or temporary locations can establish this connection.

And finally, marketplace facilitator laws can come into play. If you sell through Amazon, Etsy, eBay, or another third-party platform, many states require the platform to collect and remit tax on your behalf. But you may still need to register, file returns, or track sales thresholds for non-marketplace sales.

Register Once Nexus Is Triggered

Once you’ve triggered nexus in a state, you’re required to register for a sales tax permit before you begin collecting tax. In New York, this means registering with the Department of Taxation and Finance and collecting both state and local taxes.

New York City, in particular, has one of the highest combined rates—currently 8.875%—which includes state, city, and transit district taxes. Depending on your product or service, the taxability may vary. For example, clothing under $110 is exempt from New York State sales tax but not necessarily from NYC’s local tax.

For other states, registration processes differ, and some even require separate filings for cities or counties (especially in “home rule” states like Colorado). This is where tax software or the support of a professional can be invaluable.

Collect, Remit, and Record Properly

After registration, you’ll need to collect the correct sales tax rate at checkout—based on the buyer’s location, not yours. This includes both state and applicable local taxes, which can vary widely.

You’ll then file returns—monthly, quarterly, or annually depending on the state’s rules—and remit the tax you’ve collected. Each state has its own deadlines and filing requirements.

Just as important as collection is documentation. Keep accurate, well-organized records of:

• Sales data broken down by state
• Exemption certificates (if you sell to wholesalers or tax-exempt organizations)
• Copies of returns filed and confirmation of payment

Should you ever face an audit—either from New York or another state—having this information readily accessible can help resolve the situation quickly.

Monitor Ongoing Nexus Risk

Your nexus footprint can evolve quickly. You might not have obligations in California or Florida this month—but one strong quarter could change that. That’s why it’s important to track sales by state throughout the year and re-evaluate nexus exposure regularly.

For NYC-based businesses, this is especially relevant if you fulfill online orders via third-party logistics warehouses (3PLs) or work with affiliate partners across the country. These arrangements can establish physical or affiliate nexus in states you may not have considered.

Some business owners conduct an annual nexus review to identify changes and ensure timely registration. Many also use tax automation tools to flag thresholds and streamline reporting.

Stay Ahead of Multi-State Compliance

Sales tax compliance may not be the most exciting part of running a business—but it’s one of the most important. Failing to register or under-collecting tax can lead to penalties, interest, and costly headaches down the road.

If you’re based in New York and selling to customers in other states, there’s a good chance you’ve already triggered nexus somewhere without realizing it. And in a high-compliance state like New York, where the Department of Taxation takes enforcement seriously, it’s doubly important to stay proactive.

Being compliant protects your bottom line, enhances customer trust, and gives you room to grow without surprises.

Final Thoughts

Sales tax for online businesses isn’t one-size-fits-all. For New York–based businesses, compliance means not only meeting state and local rules here at home, but also keeping an eye on your national reach.

With proper tracking, timely registration, and solid documentation, you can navigate multi-state sales tax with confidence.

Need help managing compliance in New York or beyond? The Holtz Group helps online businesses stay ahead of their sales tax obligations—so you can focus on growing your business, not paperwork.