How to Handle Sales Tax If You Sell in Multiple States

Selling to customers across state lines can open exciting growth opportunities for your business—but it also creates new sales tax responsibilities. For many business owners, multistate sales tax compliance can quickly become confusing.

If your business sells products or taxable services in more than one state, understanding when you need to collect, file, and remit sales tax is essential. Here’s what you need to know.

1. Understand Sales Tax Nexus

“Nexus” is the connection between your business and a state that creates a sales tax obligation.

There are two main types:

Physical Nexus

You may have physical nexus if you:

• Have an office, store, warehouse, or inventory in the state

• Employ remote workers there

• Attend trade shows or events regularly

• Use third-party fulfillment centers

Economic Nexus

Most states also impose economic nexus rules. This means you may need to collect sales tax based on:

• Total sales revenue in the state

• Number of transactions with customers in the state

For example, a state may require registration once you exceed $100,000 in sales or

200 transactions annually.

2. Know Which States Require Collection

Not every state has the same rules:

• Sales tax rates vary by state, county, and city

• Some states tax services, while others do not

• Certain products may be exempt or taxed differently

You should:

• Track where your customers are located

• Monitor sales thresholds regularly

• Review each state’s tax rules before expanding

3. Register Before You Start Collecting

Once you establish nexus, you generally need to register for a sales tax permit in that state before collecting tax.

Important:

• Do not collect sales tax without proper registration

• Register as soon as you meet the threshold

• Keep records of registration dates and account numbers

Late registration can lead to penalties and back taxes.

4. Set Up Accurate Sales Tax Collection Systems

Handling multistate sales tax manually can become overwhelming as your business grows. Tax rates change frequently, and errors in collection can add up quickly.

Using reliable accounting software or sales tax automation tools can help ensure accurate rates at checkout, proper tax categorization for your products or services, and monthly reconciliation of taxes collected.

5. Keep Detailed Records

Strong recordkeeping helps protect your business during audits.

Maintain:

• Sales by state

• Exemption certificates

• Customer invoices

• Marketplace sales reports

• Tax returns filed

Good documentation can save significant time and money if questions arise later.

6. Consider Professional Support

Multistate sales tax rules are complex and constantly evolving. As your business expands, working with a tax and accounting professional can save you time, reduce risk, and give you peace of mind.

A knowledgeable advisor can help you identify nexus, register in the right states, set up efficient systems, and ensure returns are filed correctly.

Final Thoughts

Selling in multiple states can help your business grow—but it also increases your tax responsibilities. Understanding nexus, tracking thresholds, and staying organized are key to avoiding penalties and protecting your bottom line.

If your business is expanding into new markets, proactive sales tax planning can help you stay compliant and focused on growth.