Sales Tax Nexus Made Easy: A Comprehensive Guide

For businesses that operate in multiple states, understanding sales tax nexus is incredibly important. Sales tax nexus refers to the connection between a business and a state that obligates the business to collect sales tax from customers in that state. This connection can be established in several ways, such as having a physical presence, generating revenue above a certain threshold, or employing workers in that state. 

It may sound complicated, but a comprehensive guide is here to make the concept simpler to grasp. Its main goal is to offer a clear and easy-to-understand explanation of how sales tax nexus can have a significant impact on the everyday operations and tax obligations of businesses.

Understanding Sales Tax

Sales tax is a concept familiar to most Americans, but if you’re considering opening a business in the United States and you’re from another country, you might not be acquainted with the taxation rules. In simple terms, sales tax is the additional amount you see tacked onto your purchase total at the cash register, and it plays a vital role in financing various government services. In the United States, sales tax is administered at the state level, and sometimes even at the local level.

When you run a business in the U.S., you’ll typically be responsible for collecting sales tax from your customers and then remitting it to the relevant tax authorities. This process is of utmost importance for a couple of key reasons. 

First and foremost, revenue generated from sales tax is a significant source of income for state and local governments. It’s the financial backbone that supports crucial services like education, infrastructure development, and public safety. Secondly, by collecting and remitting sales tax, businesses ensure that they are contributing their fair share to the communities in which they operate.

In essence, comprehending sales tax is not just about adhering to legal requirements; it’s also about being an active participant in the financial well-being of the regions where your business operates. It’s an integral part of the economic landscape in the United States, and understanding and managing it properly is essential for any business, whether it’s local or international.

What Is the Sales Tax Nexus?

The importance of knowing your business’s sales tax nexus cannot be overstated. It not only helps in fulfilling legal requirements but also in planning financial strategies. Ignorance of these rules can lead to penalties, audits, and even litigation.

There are different types of nexus, including physical, economic, and affiliate. Physical nexus is established if a business has a tangible presence, like an office or warehouse, in a particular state. Economic nexus focuses on revenue generation, and the thresholds can vary from state to state. Affiliate nexus, on the other hand, relates to relationships with in-state entities that help a business make sales.

In recent years, the rules for determining sales tax nexus have evolved. The landmark 2018 Supreme Court ruling in South Dakota v. Wayfair expanded states’ ability to enforce their sales tax laws on out-of-state sellers, making it vital for businesses to stay updated on these changing regulations.

Compliance with sales tax nexus rules involves multiple steps, including registration, tax collection, and periodic filing. Companies can use specialized software or consult with tax professionals to ensure they are meeting all obligations.

With regulations continuously changing, it is best to consult professionals or use dedicated software for compliance to avoid legal repercussions.

2 Types of Nexus

When it comes to sales tax in the United States, there are two primary types of nexus that businesses need to be aware of. These distinct categories determine whether a business is obligated to collect and remit sales tax in a particular state.

Physical Nexus

Physical nexus, as the name suggests, is established through a physical presence in a state. This presence can take various forms, including having a brick-and-mortar store, warehouse, or office in a state. Additionally, attending trade shows or having employees working in a state can also trigger physical nexus.

Common business activities that create physical tax nexus include:

  • Maintaining a physical store: If your business has a physical storefront or office in a state, you likely have a physical nexus there.
  • Warehousing inventory: Storing your products in a warehouse within a state’s borders can create a physical nexus.
  • Having employees: Employing workers who operate within a state often establishes a physical nexus.
  • Participating in trade shows: Attending trade shows in a state may trigger physical nexus, depending on state laws.

Economic Nexus 

On the other hand, economic nexus is a concept that has gained prominence in recent years. It doesn’t rely on physical presence but instead hinges on economic activity within a state. Economic nexus is typically determined by the volume of sales or transactions a business conducts in a state. States have varying thresholds that trigger economic nexus, often based on a certain amount of sales revenue or a specific number of transactions.

Once a business establishes a sales tax nexus, whether through physical presence or economic activity, it becomes legally obligated to collect sales tax from buyers in that state. This obligation is vital to ensure compliance with state tax laws and regulations.

Why Is Sales Tax Nexus Important?

Understanding and addressing the sales tax nexus is crucial for several reasons:

Legal Compliance: Failure to collect and remit sales tax when required can result in penalties and legal consequences. By understanding your nexus obligations, you can avoid potential legal issues.

Financial Responsibility: Sales tax revenue is a significant source of income for states and local governments. By collecting and remitting sales tax, your business contributes to the funding of essential services like education, infrastructure, and public safety in the communities where you operate.

Competitive Advantage: Properly managing sales tax obligations can help your business stay competitive. Customers often prefer transparent pricing that includes sales tax, and compliance can build trust with your audience.

Avoiding Audit Risks: Ignoring the sales tax nexus can increase the risk of tax audits. Proactively addressing your sales tax responsibilities reduces this risk and the associated costs and stress.

When to Register for a Sales Tax License?

Stay informed about the specific rules and thresholds for each state where you conduct business, as they can vary significantly. Failing to register for a sales tax license when required can lead to legal and financial consequences, so it’s advisable to consult with tax professionals or the relevant state tax authorities to ensure compliance with sales tax regulations in each jurisdiction. Discussed below are scenarios when you’ll need to register for a sales tax license:

When Your Business Has a Physical Presence in a State:

You should register for a sales tax license in a state when your business establishes a physical presence there. This physical presence can take various forms, such as having a brick-and-mortar store, an office, a warehouse, or employees working within the state. 

Essentially, if your business has a tangible connection to a state, it likely triggers the requirement to collect and remit sales tax. It’s important to note that the specifics of what constitutes a physical presence can vary from state to state, so it’s advisable to consult the tax authorities or a tax professional to determine your obligations in each jurisdiction.

When Your Business Has an Economic Nexus in a State:

You should also consider registering for a sales tax license when your business establishes an economic nexus in a state. Economic nexus is determined by the volume of sales or transactions your business conducts within a state, regardless of whether you have a physical presence there. 

States have varying thresholds for economic nexus, often based on a certain amount of sales revenue or a specific number of transactions. Once your business exceeds these thresholds in a particular state, you are typically required to register for a sales tax license and collect and remit sales tax on applicable sales in that state.

When You Sell on a Marketplace and Have Nexus in a State without a Marketplace Facilitator Law:

If your business sells products on an online marketplace like Amazon, eBay, or Etsy, and you have a sales tax nexus in a state that does not have a marketplace facilitator law, you may need to register for a sales tax license independently. In states with marketplace facilitator laws, the responsibility for collecting and remitting sales tax often falls on the marketplace itself. 

However, in states without such laws, the obligation may rest with individual sellers who meet the criteria for sales tax nexus. In this case, you should monitor your sales in that state and register for a sales tax license once you meet the nexus threshold.

How to Register for a Sales Tax Permit?

Registering for a sales tax permit is a necessary step for businesses that need to collect and remit sales tax. Here’s a general step-by-step process:

  1. Determine Your Nexus: Before registering, determine in which states you have a sales tax nexus. This could be due to physical presence, economic activity, or other factors as discussed earlier.
  1. Visit the State’s Tax Agency Website: Go to the website of the state’s tax agency where you have nexus. Each state typically has its own process for registration, and you can find the necessary forms and information on their websites.
  1. Complete the Application: Fill out the sales tax permit application form provided by the state. Be prepared to provide essential business information, such as your business name, address, federal employer identification number (FEIN), and details about the products or services you sell.
  1. Submit the Application: Submit the completed application to the state tax agency. This can often be done online, but some states may require paper submissions.
  1. Wait for Approval: After submitting your application, you may need to wait for the state to review and approve it. The processing time can vary by state.
  1. Receive Your Sales Tax Permit: Once your application is approved, you will receive your sales tax permit from the state. This permit will typically include important details such as your permit number and the reporting frequency for filing sales tax returns.
  1. Comply with Reporting Requirements: Ensure you understand the state’s sales tax filing and payment schedule, and adhere to it. Collect the appropriate amount of sales tax from your customers on taxable sales and remit it to the state as required.

How Does Sales Tax Work?

Sales tax operates differently depending on the type of business or the nature of the transaction involved. From wholesalers to digital product vendors, each category has unique guidelines to follow. Here’s a closer look at how sales tax works for various business models:


Wholesalers typically do not charge sales tax on their sales to retailers or other businesses because the sales tax is ultimately collected when the end consumer makes a purchase from the retailer. This is known as a “resale exemption.”


In dropshipping, sales tax considerations can become complicated as three parties are typically involved: the supplier, the retailer, and the customer. The sales tax obligation often depends on the location of these entities and the nexus rules of the states involved. Generally, the retailer is responsible for collecting and remitting the sales tax, but it’s crucial to verify specific state laws.


Sales tax for SaaS varies greatly from state to state. Some states consider SaaS to be a taxable service, while others do not tax it at all. Given the cloud-based nature of SaaS, determining nexus can be challenging. Companies need to be aware of the specific rules in each state where they have customers.

Digital Products

Sales tax on digital products like e-books, streaming services, or downloadable software is an evolving landscape. While some states have clear guidelines, others are still catching up with the digital age. Generally, the tax is determined by the customer’s location, but this can vary.


For services like consulting or home repairs, the application of sales tax varies significantly. Some states tax services, while others exempt them. In some instances, only specific services may be subject to sales tax. Companies must be familiar with the laws in the states where they provide services to ensure compliance.

Let doola Help You Navigate the Sales Tax Maze 

Understanding the sales tax nexus and its variations across different business types can be a complex undertaking, but it’s a crucial aspect of running a multi-state business successfully. Non-compliance isn’t an option; it can lead to penalties, audits, and even legal action.

This is where doola comes in, simplifying the convoluted world of sales tax. By offering tailored bookkeeping solutions that consider your specific business model, doola helps eliminate confusion and ensures that you stay compliant with the ever-changing state regulations. From identifying your tax obligations to assisting with registration and periodic filing, doola provides a one-stop solution for all your sales tax needs.


How should I use and accept resale certificates?

Resale certificates are documents that prove a purchase is made for resale, thus exempting the buyer from sales tax. If you’re a seller, it’s necessary to collect completed resale certificates from eligible buyers and keep these records on file to validate the tax-exempt sales during an audit.

What is a use tax?

Use tax is a type of tax applied to items purchased outside one’s home state but used within that state. It is generally the responsibility of the consumer to report and pay this tax, usually at the same rate as the state’s sales tax.

What is a consumer tax?

Consumer tax refers to the tax levied on goods and services that are consumed or used by individuals, rather than businesses. This includes sales tax, excise tax, and value-added tax (VAT), and it is generally collected at the point of sale.

Do I need to have a sales tax nexus in every state?

No, you only need to have a sales tax nexus in states where you have established a significant connection through physical presence, revenue, or employees. Each state has its own nexus laws and criteria, so you’ll need to review the regulations for each state where you conduct business.

What happens if I ignore the sales tax nexus?

Ignoring your sales tax nexus obligations can result in serious consequences, including penalties, audits, and legal action. States can retroactively collect taxes, along with fines and interest, so it’s important to understand and comply with each state’s sales tax nexus laws to avoid costly repercussions.

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