Sales tax nexus: Multi-state compliance guide

Published 30 January 2026

Table of contents

• What is sales tax nexus?
• What triggers the sales tax nexus rules?
• How to stay compliant across states
• Sales tax rules for specific sellers, products and services
• Make sales tax simpler with Xero
• FAQs on sales tax nexus

Key takeaways

• Sales tax nexus applies if your business meets physical location or economic (sales) tests in states where the business operates. If you have nexus, you must register for a sales tax account, file returns, and collect and remit sales tax.
• Most states define physical nexus as having retail locations, property, equipment, inventory, or employees in the state.
• Economic sales tax nexus rules apply if you cross a certain dollar value or number of sales. The rules vary by state, so check with the local departments of revenue or a similar authority.
• Track sales carefully and make sure you understand what triggers nexus in each state.
• Software like Xero helps you track sales based on location, calculate sales tax rates in multiple areas, and generate reports so you can file prompt and accurate sales tax returns.

What is sales tax nexus?

The word nexus means connection – sales tax nexus is when a business's connection with a state triggers an obligation to collect and pay sales tax. If you have sales tax nexus – physical, economic, or both – you must collect sales tax from customers in that state and file sales tax returns.

What triggers the sales tax nexus rules?

There are a few different ways to trigger sales tax nexus – but the rules vary from state to state. If you do business in multiple states, you need to be aware of the unique rules in each state.

To find out the nexus rules in each state where you do business, check the IRS’s links to state revenue agencies. What kind of physical presence triggers nexus?

Most states share standard rules for physical nexus. In all states, if you have a brick-and-mortar retail store, you have nexus. In most states, you can also trigger physical nexus if you own property, store inventory, or employ people in the state.

Sometimes, physical nexus is temporary – for instance, if you're selling items at a special event, like a fair or trade show.

What is economic nexus?

Economic nexus is a legal and tax concept that means a business has a tax obligation in a state or country because of its economic activity there, even if it has no physical presence (like an office or employees). Since the South Dakota v. Wayfair, Inc. ruling, all states with sales tax have created economic nexus rules for remote sellers.

Depending on the state, you may trigger economic nexus by:

• sales volume or number of transactions
• crossing a dollar or transaction threshold, or to be over both thresholds

The economic nexus numbers and thresholds vary by state – many states apply when you have over $100,000 in sales, but in others, economic nexus doesn't kick in until you reach $500,000 in sales. For states with transaction thresholds – the number tends to be 100 or 200 transactions.

Do click-through or affiliate programs trigger nexus?

In a few states, even if you don't meet the physical or economic nexus thresholds, your affiliates there can trigger what’s known as “click-through nexus” – meaning you have to register for a sales tax account and collect sales tax from customers there.

Click-through nexus thresholds range from $2000 to $50,000. So if you have an online affiliate based in New York (the first state to implement a click-through nexus law), and their links generate New York sales greater than $10,000, that gives the company nexus in New York, meaning it must register for a New York sales tax account.

Sales tax rules for local home-rule areas

As well as sales tax nexus by state rules, some local areas, called home-rule areas, administer their own sales taxes and often have unique requirements for remote sellers.

For more info, check out these local government pages for Alabama, Colorado, Idaho, Illinois, and Louisiana. Some parts of Chicago have home-rule sales tax, too.

How to stay compliant across states

To avoid interest and penalties (and to protect your right to do business in the state), you need to understand the rules. Keep these tips in mind.

1. Confirm thresholds and effective dates. Check the economic threshold limits in each state where you make sales against the number and amount of sales you make there. Look at the timing for when to count sales in different states.

2. Register with state tax authorities. Once you cross the thresholds, make sure you register for a sales tax account in each state. But some states are part of the Streamlined Sales Tax Registration System (SSTRS), which lets you set up accounts in multiple states at the same time for free.

Check with the Streamlined Sales Tax Governing Board, Inc. to see if your state is part of the SSTRS. If not, you’ll need to register directly with the state.

3. Configure your sales channels to collect tax correctly. Make sure you have software that lets you:

• track and calculate sales tax in multiple jurisdictions
• track sales in different channels so you know when you cross the threshold in each state

4. File returns and remit on time. The due dates and filing frequency (monthly, quarterly, or annually) vary from state to state, so set reminders to make sure you file and pay on time. You can also automate the process with sales tax software like Xero.

Here’s how Xero can automate your sales tax calculations.

5. Maintain records and monitor changes in local tax laws. Keep records in case you're audited. Even before registering in a state, you should keep records in case the state thinks you have nexus when you don't. Also, monitor the laws, as states frequently update their sales tax requirements and nexus rules.

Accounting software makes it much easier to keep accurate and up to date records.

Sales tax rules for specific sellers, products and services

Prior to the Prior to the South Dakota v. Wayfair, Inc. ruling, states could not require businesses to collect sales tax unless they had a physical presence in the state. In the five years since this court case, all 45 states with sales tax have adopted nexus rules for remote sellers and marketplaces.

Marketplace facilitators must collect and remit sales tax

Every state requires marketplace facilitators (or sellers) to collect and remit sales tax, but in different ways. States define marketplace facilitators differently, count marketplace sales toward economic nexus thresholds, and have special rules for certain industries.

Digital products and services

About 30 states require sellers to assess sales tax on digital products and services, but the rules vary.

For example:

• New Jersey sales tax applies to all digital products and services, like installing, maintaining, and repairing digital products.
• New York takes a hybrid approach – digital books, games, and music aren't subject to sales tax, but pre-written computer programs are.
• About 20 states completely exempt digital products from sales tax – for example, there's no Missouri sales tax on digital downloads.

Origin and destination sourcing

Most states use destination-based sales tax rules. That means the rate at the buyer's location (the destination of the goods) applies to most sales.

Make sales tax simpler with Xero

Whether you're paying sales tax in one state or dozens of states, Xero's got your back.

Xero includes sales tax rates everywhere you make sales – and it integrates with Avalara to bring you seamless sales tax calculations wherever you are. Create invoices, track collected sales tax, and generate reports with all the numbers you need to file sales tax returns.

Get one month free

FAQs on sales tax nexus

Sales tax nexus rules are complicated – here are answers to commonly asked questions about sales tax nexus.

Do I need to collect in states with no sales tax?

No. There are five states with no state-wide sales tax – Alaska, Delaware, New Hampshire, Montana, and Oregon. But check the local rules anyway. For example:

• many towns in Alaska administer local sales taxes
• Montana has sales tax on hotel rooms and lodging
• New Hampshire levies sales tax on rooms and prepared food

Do shipping fees count toward thresholds?

It depends on the state, and how it taxes shipping charges. In some states you have to apply sales tax on shipping, and some have nuanced rules where shipping is only subject to sales tax in certain situations.

Check with the Department of Revenue website in your state to find the exact rules.

Do exempt sales count toward thresholds?

It depends. Most states count exempt sales when calculating economic nexus, but it also depends on the type of exemption. Typically, you count exempt sales of property that's generally subject to sales tax, but not services exempt from sales tax. To be sure, check the rules in the state where you're making the sales.

When do thresholds reset?

The rules vary. Some states require you to check the past 12 months of sales every month, while others only want you to look at the past 12 months of sales at the end of every quarter. Once you're registered for sales tax, most states require you to collect and file sales tax returns even if your sales dip under the threshold. Others base their current year's filing requirements on your sales for the previous year, meaning that you may lose nexus if you're under the threshold for 2 years.

Check with the local Department of Revenue to get the exact rules in the state where you’re doing business.

Does marketplace collection mean I don’t have to register?

Yes – that's the case in most states. Usually, marketplace facilitators collect and remit sales tax on behalf of their sellers. But if you have other sales into the state (like sales from your own website), you may need to count those sales as well as the marketplace sales when calculating your threshold. Check the laws in each state to make sure you're compliant.

What triggers a sales tax audit?

State auditors look at returns filed with the state, but they also audit sales tax registrations to spot businesses that haven't been filing. The biggest triggers for sales tax nexus audits are:

• discrepancies between records from marketplace facilitators
• customs reports
• information from other government agencies

Auditors also look to make sure that businesses meet the physical presence tests, such as storing inventory or having employees in the state.