When do I need to register for US sales tax?
📋 Direct Answer
[Unverified] Figures may be out of date. Queued 2026-08-21 (uvq-us-sales-tax-when-to-register-en-F0-05). Check the official page: https://www.mtc.gov/. Public compilation, not tax advice.
Check the official pageYou need to register for US sales tax when you establish nexus in a state. This happens when: (1) you have physical presence (FBA warehouse, office, employees), or (2) you exceed economic nexus thresholds ($100K sales or 200 transactions in most states). Register BEFORE you exceed thresholds — states can audit retroactively. Registration is per-state. Cost: free registration, but you'll need sales tax software ($20-100/month) to manage multi-state filing.
📝 Step-by-Step Guide
Prerequisites
- •State Registration
- 1
State Registration - Step 1
Determine which states have nexus
- 2
State Registration - Step 2
Register with each state's Department of Revenue
- 3
State Registration - Step 3
Set up sales tax accounts and filing schedules
- 4
Sales Tax Software - Step 1
Use tax automation software (TaxJar, Avalara, etc.)
- 5
Sales Tax Software - Step 2
Automate tax rate calculation and filing
- 6
Sales Tax Software - Step 3
Integrate with your e-commerce platform
💰 Cost Breakdown
| Item | Cost | Frequency |
|---|---|---|
| Marketplace facilitator collection | Included in platform fees | one-time |
| Direct registration + collection | $500-5,000/year per state for compliance software + filing | annual |
| State Registration | Free | one-time |
| Sales Tax Software | $20-100/month | monthly |
| Total Estimate | $520 – $5100 | Per US filing |
Once nexus exists, you owe tax from that point forward — retroactive liability can be substantial
States can assess back taxes for 3-4 years plus penalties and interest at 1-2% per month
🛡️ Prevention Steps
- ✓Monitor nexus triggers monthly
- ✓Register proactively, not reactively
- ✓Consider voluntary disclosure for historical exposure
Item by Item
RequiredState RegistrationFree1-2 weeks per state
- 1Determine which states have nexus
- 2Register with each state's Department of Revenue
- 3Set up sales tax accounts and filing schedules
RecommendedSales Tax Software$20-100/month1-2 weeks
- 1Use tax automation software (TaxJar, Avalara, etc.)
- 2Automate tax rate calculation and filing
- 3Integrate with your e-commerce platform
Comparison
| Marketplace facilitator collection | Direct registration + collection | |
|---|---|---|
| Pros |
|
|
| Cons |
|
|
| Best For | Sellers primarily on Amazon, Walmart, or other marketplaces | Sellers with significant direct-to-consumer sales |
| Est. Cost | Included in platform fees | $500-5,000/year per state for compliance software + filing |
Common Mistakes
❌ Waiting to register until sales are 'significant' — nexus is triggered at specific thresholds, not at your discretion
💥 Consequence: Retroactive liability from the moment nexus was triggered, with penalties
✅ Fix: Register as soon as nexus is triggered — thresholds are objective, not subjective
❌ Registering too early in states with no nexus — wastes money on compliance costs
💥 Consequence: Unnecessary filing obligations and software costs
✅ Fix: Only register where nexus actually exists based on objective criteria
Seller Paths
Determine Registration Timing
- 1. Check each state's economic nexus threshold
- 2. Monitor sales approaching threshold
- 3. Register 30 days before exceeding (most states)
- 4. Set up collection from day one of registration
Proactive Registration Strategy
- 1. Register in top 5 states by sales volume first
- 2. Expand registration as sales grow
- 3. Use marketplace facilitator for smaller states
- 4. Annual review of registration requirements
Next Steps
Get a free compliance assessment
Continue →Related Tools
Related Questions
Sources
- • Multi-State Tax Commission
- • Individual state DOR websites
Disclaimer: This page is for informational purposes only and does not constitute legal or tax advice. Consult a professional for your specific situation.