Sales Tax Rules Just Changed Here’s What Every Online Seller Needs to Know in 2025

Introduction

In 2025, sales tax rules across the U.S. are more complex than ever especially for online sellers. Platforms like Amazon, Shopify, Etsy, and Walmart may collect and remit sales tax on your behalf, but you’re still responsible for knowing where you have nexus, when to register, and how to remain compliant with state tax agencies. This blog breaks down the #1 nexus tip, when to act, and how to avoid costly penalties and interest.

Nexus Laws & IRS Tax Code Reference

While sales tax is a state-level obligation and not directly handled by the IRS, it intersects with federal compliance in the following ways:

• IRC §6001: Requires business owners to maintain proper books and records, including sales tax collections.
• Wayfair v. South Dakota (2018): U.S. Supreme Court decision that gave states the power to enforce sales tax collection based on economic nexus, not just physical presence.
• State Sales Tax Codes: Each state has its own economic nexus threshold, usually based on sales volume or transaction count.

State-Level Compliance

Common thresholds across states in 2025:

• $100,000 in gross revenue, or
• 200+ separate transactions shipped into the state annually.

If your sales meet either condition in a state, you likely have nexus and must register and collect sales tax there even if you’re not physically located in that state.

Real-World Example: Marketplace Seller & Nexus

Case: Jessica, Shopify + Etsy Seller in Florida

• 2024 Sales Breakdown:
  • Florida: $40,000
  • California: $110,000
  • New York: $25,000 (190 transactions)
  • Texas: $95,000

Jessica has economic nexus in California (by revenue) and New York (by transaction count).

She:

• Registered for sales tax permits in CA and NY
• Integrated Shopify Sales Tax Settings and Etsy remittance tools
• Filed state-level sales tax returns quarterly
• Kept records as required under IRC §6001

Result: No late filings, no penalties, and avoided registration in states where she didn’t meet thresholds.

Step-by-Step Sales Tax Compliance Guide

1. Track Your Sales by State:
   • Use your platform dashboard or accounting software to break down gross revenue and transactions by state.
2. Check Each State’s Threshold:
   • Visit the Department of Revenue for each state where you sell.
3. Register for Sales Tax Permits:
   • If you meet nexus thresholds, register before collecting sales tax.
4. Enable Sales Tax Collection on Your Platform:
   • Shopify, Amazon, Etsy, and Walmart all allow custom settings.
5. File State Sales Tax Returns:
   • File monthly, quarterly, or annually based on the state’s requirements.
6. Keep All Records:
   • Maintain documentation for collections, remittances, and exemption certificates (if applicable).

Conclusion

In 2025, every serious eCommerce seller needs to understand sales tax nexus. If you’re selling across multiple states and crossing thresholds, you must act before the state tax agencies do. The good news? With the right guidance, software, and registration strategy, you can stay compliant and penalty-free.

Call-to-Action and Disclaimer

Selling in multiple states? Not sure where you’ve triggered nexus?

Schedule a 1-on-1 session with Anshul Goyal, CPA to audit your sales activity, set up sales tax registrations, and automate your reporting.
Book here: https://calendly.com/anshulcpa/

Disclaimer: This content is for general informational purposes only. Sales tax rules vary by state. Always consult a licensed tax professional before acting on this information.

Anshul Goyal, CPA EA FCA is a U.S.-licensed CPA and IRS Enrolled Agent who helps digital sellers and Indian founders in the U.S. maintain IRS and state compliance, including multistate sales tax filings and audits.

Top 5 FAQs

1. What is sales tax nexus?
Nexus is a tax connection to a state. If you exceed sales or transaction thresholds, you must collect and remit sales tax.

2. Do marketplaces like Amazon collect sales tax for me?
Yes, for marketplace-facilitated sales. But you’re still responsible for sales from platforms like Shopify or your own website.

3. What happens if I don’t register for sales tax in a state where I have nexus?
You may face back taxes, interest, penalties, or even legal action from the state’s Department of Revenue.

4. Can one sale in a state trigger nexus?
Typically no states set clear thresholds (e.g., $100,000 or 200 transactions). But physical presence (inventory, employees) triggers immediate nexus.

5. How often do I need to file sales tax returns?
Filing frequency varies by state. It could be monthly, quarterly, or annually based on your sales volume.

About Our CPA

Anshul Goyal, CPA EA FCA is a Certified Public Accountant in the U.S., an IRS Enrolled Agent, and a Chartered Accountant from India. With 15+ years of experience, Anshul has helped over 2,000 clients including eCommerce brands and multistate sellers stay compliant, reduce penalties, and streamline filings.

Email: anshul@kkca.io
Schedule a call: https://calendly.com/anshulcpa/
Website: www.kkca.io