Picture this: Priya launches her US-based skincare brand from her apartment in Texas. She sells $250,000 through her Shopify store and Amazon. No physical presence anywhere except Texas. She thinks: “I’m only registered in Texas, so that’s the only state where I owe sales tax, right?”
Wrong. Priya has triggered economic nexus in at least 15 states—and she’s been required to collect sales tax in those states for months. Her exposure? $18,000 in uncollected sales tax, plus penalties up to 25% ($4,500), plus interest compounding monthly. Total potential liability: $25,000+.
This scenario plays out constantly for Indian entrepreneurs launching US ecommerce businesses. The rules changed fundamentally in 2018 with the South Dakota v. Wayfair Supreme Court decision, which eliminated the physical presence requirement for sales tax.
Now, selling remotely into states triggers “economic nexus”—and with it, registration, collection, and filing obligations that most founders don’t discover until it’s too late.
This guide explains everything Indian-owned ecommerce businesses need to know about US sales tax: economic nexus rules, state-by-state thresholds, marketplace facilitator laws for Amazon/Shopify sellers, multi-state exposure management, and why March 15 matters for your registration timeline.
What Changed in 2018: The Wayfair Decision
Before June 21, 2018, states could only require businesses to collect sales tax if they had physical presence (nexus) in the state—office, warehouse, employees, inventory.
The Supreme Court’s South Dakota v. Wayfair, Inc. ruling changed everything. States can now require remote sellers (online businesses with no physical presence) to collect sales tax based solely on economic activity.
What this means for you: If you sell enough products into a state—even without any physical presence there—you must register, collect sales tax from customers, and remit it to that state.
According to Sales Tax Institute, “Every state with a sales tax has economic nexus requirements for remote out-of-state sellers following the 2018 South Dakota v. Wayfair decision.”
Economic Nexus Explained: The $100,000 Threshold
Economic nexus is triggered when your sales into a state exceed certain thresholds—typically based on revenue and/or transaction count.
Most common threshold (45 states): $100,000 in annual sales OR 200 transactions
However, this is changing rapidly in 2026. Many states are eliminating the 200-transaction rule to simplify compliance.
2026 Updates: Transaction Thresholds Being Eliminated
Illinois (effective January 1, 2026): Eliminated 200-transaction threshold. Now only $100,000 in gross receipts triggers nexus.
Other states that removed transaction counts:
- Alaska
- Utah
- North Carolina
What sales count toward the threshold? This varies by state:
- Gross sales: All sales including exempt items and resale (Illinois, California)
- Retail sales: Excludes wholesale/resale (most states)
- Taxable sales: Only taxable transactions count (some states)
According to TaxCloud’s 2026 nexus guide, “What trips sellers up is that states calculate nexus differently. For example: Some states count gross sales, including exempt transactions.”
Notable Exceptions to the $100,000 Rule
States with different thresholds:
- Texas: $500,000 in annual gross revenue (highest threshold)
- Alabama: $250,000 for marketplace facilitators
- California: $500,000 in sales (second highest)
- New York: $500,000 in sales AND 100 transactions (both required)
- Connecticut: $100,000 in sales AND 200 transactions (both required)
State-by-State Economic Nexus Quick Reference
States with ONLY revenue threshold (no transaction count):
- Illinois: $100,000
- Indiana: $100,000
- Pennsylvania: $100,000
- Texas: $500,000
- California: $500,000
- Florida: $100,000
- Ohio: $100,000
- Virginia: $100,000
States requiring BOTH thresholds to be met:
- New York: $500,000 AND 100 transactions
- Connecticut: $100,000 AND 200 transactions
Most other states: $100,000 OR 200 transactions (whichever comes first)
Important: These thresholds are measured over a 12-month period—either calendar year, prior calendar year, or rolling 12 months (varies by state).
Real-World Scenarios: When You Trigger Nexus
Scenario 1: Shopify Store Selling Nationwide
Rajesh operates a Shopify store selling phone accessories from Delaware. 2025 sales by state:
- California: $125,000 (1,250 orders)
- New York: $95,000 (950 orders)
- Texas: $85,000 (850 orders)
- Florida: $110,000 (1,100 orders)
- 30 other states: $580,000 combined
- Total: $995,000
States where Rajesh has economic nexus:
- California: ✓ ($125K > $500K threshold? No, but $125K > $100K in some interpretations)
- Florida: ✓ ($110K > $100K)
- New York: ✗ (needs $500K AND 100 transactions—has transactions but not revenue)
- Texas: ✗ (needs $500K, only has $85K)
- Likely 8-12 other states from the $580K pool (depends on individual state sales)
Action required: Register in Delaware (physical nexus) + 10-15 states with economic nexus = 11-16 total registrations
Scenario 2: Amazon FBA Seller
Vikram sells kitchen products via Amazon FBA. Amazon stores his inventory in 8 fulfillment centers across US. 2025 sales: $500,000.
States where Vikram has nexus:
- Physical nexus: All 8 states with Amazon FBA warehouses (Amazon moves inventory automatically)
- Economic nexus: Any states where sales exceed thresholds
- Total: Likely 15-20 states
Good news: Amazon (as marketplace facilitator) collects and remits sales tax on his behalf in all states with marketplace facilitator laws (all 45 states with sales tax).
Action required: Potentially register in states with FBA inventory (varies by state rules), but Amazon handles collection.
Scenario 3: Multi-Channel Seller (Danger Zone)
Anita sells handmade jewelry through:
- Amazon: $300,000
- Own Shopify store: $200,000
- Etsy: $100,000
- Total: $600,000
Sales tax responsibility:
- Amazon sales: Amazon collects and remits (marketplace facilitator)
- Etsy sales: Etsy collects and remits (marketplace facilitator)
- Shopify sales: Anita is 100% responsible (Shopify is NOT a marketplace facilitator for main Shopify stores)
Critical problem: Amazon and Etsy sales may push Anita over economic nexus thresholds in states. Some states COUNT marketplace sales toward nexus calculation even though marketplace collects the tax.
Action required: Register in all states where $200K Shopify sales triggered economic nexus + possibly others where combined sales triggered nexus.
Marketplace Facilitator Laws: What Amazon, Shopify, and Etsy Handle
Marketplace facilitator laws shifted sales tax collection responsibility from third-party sellers to the platforms themselves.
All 45 states with sales tax now have marketplace facilitator laws.
Who IS a Marketplace Facilitator
Platforms that collect and remit sales tax on your behalf:
- Amazon (including FBA)
- Walmart Marketplace
- eBay
- Etsy
- Shopify Shop App (separate from main Shopify store)
- Target Plus
- Wayfair
- Wish
According to Avalara’s marketplace facilitator guide, “These laws shift the obligation to collect and remit sales tax from the seller to the marketplace platform.”
Who is NOT a Marketplace Facilitator
Platforms where YOU remain 100% responsible for sales tax:
- Shopify (main store): Software platform, not marketplace
- WooCommerce: Plugin for WordPress stores
- BigCommerce: Ecommerce platform
- Wix: Website builder with ecommerce
- Squarespace: Website platform
- Magento: Open-source platform
IMPORTANT EXCEPTION: Shopify’s Shop App (the mobile shopping app, NOT your main Shopify store) IS a marketplace facilitator as of January 2025. Shop App sales have sales tax collected automatically.
According to Wipfli’s marketplace facilitator analysis, “Some platforms, such as Shopify, WooCommerce and Wix, are not marketplace facilitators, meaning they only provide the tools and software for sellers to create their own online stores but do not facilitate the transactions.”
What Marketplace Facilitators Do
When you sell through a marketplace facilitator:
- They calculate sales tax at checkout (correct state/local rate)
- They collect sales tax from customer
- They file sales tax returns in all states
- They remit sales tax to state governments
- They handle audits if states question tax collected
You get: Sales reports showing tax collected on your behalf
You don’t: Collect tax, file returns, or send payments for those marketplace sales
Multi-Channel Seller Complexity
Here’s where it gets tricky for Indian entrepreneurs running multi-channel operations:
Problem #1: Do marketplace sales count toward economic nexus?
Answer: Sometimes yes, sometimes no—varies by state.
- States that INCLUDE marketplace sales in nexus calculation: California, Massachusetts, others
- States that EXCLUDE marketplace sales: Illinois, Texas, others
Example consequence:
- $90K in Amazon sales (marketplace collects tax)
- $15K in Shopify sales (you collect tax)
- California: Counts both toward $100K threshold → You have nexus, must register and collect on Shopify sales
- Illinois: Only counts $15K Shopify sales → No nexus yet
Problem #2: Must you still register even if marketplace collects everything?
Answer: Usually yes, but you file “zero returns” or “non-collecting seller” status.
Even if Amazon collects 100% of your sales tax, many states still require:
- Sales tax registration/permit
- Filing periodic returns (showing $0 tax owed because marketplace collected)
- Or registering as “non-collecting seller”
Common Ecommerce Business Models and Sales Tax Responsibilities
Model 1: Amazon FBA Only
Sales tax responsibility: 0-10%
- Amazon collects in all 45 states with marketplace facilitator laws
- May need to register in states with FBA inventory (physical nexus)
- Generally lowest compliance burden
Model 2: Shopify Store Only
Sales tax responsibility: 100%
- You register in every state where you have nexus
- You collect tax at checkout (Shopify can calculate, but YOU collect)
- You file returns and remit payments
- Highest compliance burden
Model 3: Amazon + Shopify (Most Common for Indian Entrepreneurs)
Sales tax responsibility: Complex
- Amazon: Platform collects
- Shopify: You collect
- Must track combined sales to determine nexus
- Must register in states triggered by Shopify sales
- May need to register in additional states if combined sales trigger nexus
Model 4: Dropshipping
Sales tax responsibility: 100% (usually)
- You are the seller of record
- Responsible for collecting/remitting tax
- Supplier ships but doesn’t handle tax
- Similar burden to Shopify-only model
Multi-State Registration: When and How
When to Register in a State
Register IMMEDIATELY when:
- You exceed economic nexus threshold in that state
- You establish physical presence (inventory, office, employee)
- You attend trade shows/events in that state (temporary physical nexus)
Most states require: Registration and collection starting the first day of the month AFTER you cross threshold, or immediately (varies by state).
Example: You cross $100K in Texas on February 15, 2026. You must register by March 1 and begin collecting tax March 1.
How to Register (State-by-State Process)
General registration process:
- Visit state’s Department of Revenue website
- Complete sales tax registration application
- Provide: EIN, business address, ownership info, start date
- Pay registration fee (if any): $0-$100 depending on state
- Receive sales tax permit/license
- Begin collecting tax immediately
Processing time: 1-6 weeks (varies by state)
Cost per state: $0-$100 registration + ongoing filing burden
States Requiring Upfront Bonds or Deposits
Some states require security deposits for remote sellers:
- Alabama: May require bond
- Connecticut: May require bond
- Nevada: Requires bond for some businesses
Bond amounts: $1,000-$50,000 (based on estimated tax liability)
Filing Frequencies and Deadlines
States assign filing frequency based on tax volume:
- Monthly: High-volume sellers ($1,000+ monthly tax)
- Quarterly: Medium-volume ($200-$1,000 monthly)
- Annual: Low-volume (under $200 monthly)
Due dates typically: 20th of month following period (e.g., Q1 due April 20)
Filing requirements: Must file even if $0 sales (“zero returns”)
Why March 15 Matters for Your Sales Tax Registration
March 15 isn’t just the S-Corp tax deadline—it’s a critical planning date for ecommerce sellers.
Key reasons March 15 is important:
1. Q1 Sales Trigger Nexus
If your January-March 2026 sales push you over thresholds in new states, you need to register by April 1 to collect tax starting April 1.
Example: You hit $100K in California on March 10. You must register by April 1 and start collecting April 1.
2. 2025 Tax Returns Reflect Nexus Exposure
When you file 2025 business tax returns (due March 15 for partnerships/S-Corps, April 15 for LLCs/C-Corps), you should have already registered for sales tax in states where you had nexus in 2025.
If you file federal returns showing $500K in revenue but haven’t registered for sales tax anywhere except your home state, you’re creating an audit trail showing noncompliance.
3. State Cross-Checking with IRS
States receive information from IRS about businesses operating in their jurisdiction. They cross-reference this with sales tax registrations.
Red flag scenario:
- Your Form 1120-S shows $800K revenue
- Your payment processor (Shopify Payments, Stripe) reports transactions to states
- State sees sales into their state but no sales tax registration
- Result: Nexus notice and audit
4. Strategic Planning Window
March 15 gives you time to:
- Analyze 2025 sales by state
- Determine which states you triggered nexus
- Register in those states before Q2 begins
- Implement proper tax collection going forward
- Avoid back-tax exposure for 2026
Penalties for Non-Compliance
What happens if you don’t register and collect sales tax?
Penalty Structure (Typical)
Uncollected sales tax liability:
- You owe the full amount of tax you should have collected
- Cannot go back and collect from customers
- You pay out of pocket
Late filing penalty: 5-25% of tax owed
Late payment penalty: 10-25% of tax owed
Interest: 8-12% annually (compounding)
Failure to register penalty: $50-$500 per month
Example calculation:
- Uncollected sales tax: $20,000
- Late penalty (20%): $4,000
- Interest (12% for 2 years): $4,800
- Total owed: $28,800
Criminal Penalties (Rare but Possible)
Willful failure to collect/remit sales tax can result in:
- Personal liability for owners
- Misdemeanor charges
- Fines up to $25,000
- Jail time (extreme cases)
Voluntary Disclosure Agreements (VDA)
If you discover you should have been registered but weren’t:
Don’t just register going forward. States can assess back taxes for prior years.
Better approach: Voluntary Disclosure Agreement (VDA)
VDA benefits:
- Limited lookback period (3-4 years vs 6-10 years)
- Penalty waivers (often 100%)
- Interest reduction (sometimes)
- Anonymous application process
- No criminal prosecution
VDA process:
- Submit anonymous VDA application to state
- State reviews and approves
- Reveal business identity
- Register for sales tax
- Pay back taxes for limited period (typically 3-4 years)
- Begin forward compliance
Cost: Much lower than full audit exposure
Sales Tax Automation Solutions
Manual sales tax compliance across 20+ states is nearly impossible.
Recommended automation platforms:
TaxJar (Most Popular for Shopify)
- Integrates with Shopify, Amazon, eBay, others
- Automatic rate calculation
- Economic nexus monitoring
- AutoFile in 40+ states
- Cost: $19-$199/month
Avalara
- Enterprise-grade solution
- Multi-channel support
- Returns filing service
- Cost: Quote-based (typically $500-$2,000/month)
TaxCloud
- Free for small sellers
- Basic rate calculation
- Streamlined sales tax program
- Cost: Free (with volume limits)
Shopify Tax
- Built into Shopify (if you use Shopify Payments)
- Automatic rate calculation
- Filing service available
- Cost: Included with Shopify Payments
Action Plan: What Indian Entrepreneurs Must Do Now
Step 1: Analyze 2025 Sales by State (By March 15)
- Pull sales reports from all channels
- Organize by customer state
- Calculate total sales per state
- Compare against economic nexus thresholds
- Identify states where you exceeded thresholds
Step 2: Register in Nexus States (March-April)
- Prioritize high-sales states first
- Complete registration applications
- Set up tax collection in shopping carts
- Configure automation tools
Step 3: Implement Collection Systems (Immediately)
- Enable tax collection in Shopify/WooCommerce
- Verify Amazon is collecting (if FBA seller)
- Set up TaxJar or similar automation
- Test checkout to confirm tax calculates correctly
Step 4: Set Up Filing Calendar (By April 1)
- Note filing frequency for each state
- Mark deadlines on calendar
- Set up reminders 1 week before due date
- Consider AutoFile service
Step 5: Evaluate Voluntary Disclosure (If Needed)
- If you had nexus in 2024-2025 but didn’t collect tax
- Consult sales tax attorney
- File VDA applications for affected states
- Pay back taxes with penalty waivers
How MyTaxFiler Can Help
MyTaxFiler specializes in helping Indian-owned ecommerce businesses navigate US sales tax compliance—from initial nexus analysis to multi-state registration and ongoing filing.
Why Choose MyTaxFiler:
- 15+ years handling ecommerce sales tax compliance
- Specialized expertise with Indian-owned US businesses
- Managed 500+ multi-state registrations
- Proven track record saving clients $50K-$200K in penalties
- Fixed-fee pricing (no surprises)
- Bilingual support (English/Hindi)
- Complete documentation for audit protection