Small Business Sales Tax: Nexus Rules, Collection Obligations, and Common Mistakes
Sales tax is a state and local obligation, not federal, and the rules vary dramatically across the states that impose a sales tax. The Supreme Court’s decision in South Dakota v. Wayfair, Inc. (2018) expanded sales tax collection obligations beyond physical presence. Before Wayfair, a business only needed to collect sales tax in states where it had a physical location (office, warehouse, employee). After Wayfair, states can require collection from out-of-state sellers who exceed “economic nexus” thresholds (set by each state, such as $100,000 of sales in Florida or Pennsylvania and $500,000 in California or Texas). This affects e-commerce sellers, SaaS companies, and any business selling to customers in multiple states. Service businesses are often overlooked: many states tax certain services (repair, maintenance, cleaning, landscaping, consulting), and the taxability of a service varies by state.
Sales tax nexus types:
Physical nexus (always applies):
- Office, store, warehouse in the state
- Employees working in the state (including remote employees)
- Inventory stored in the state (including Amazon FBA warehouses)
- Employees exhibiting products at trade shows (Texas counts this; rules vary by state)
- Independent sales representatives soliciting in the state
Economic nexus (post-Wayfair):
| Common Threshold | States Using This Threshold |
|---|---|
| $100,000 in sales OR 200 transactions | A shrinking group, such as Ohio (South Dakota dropped the 200 count in 2023) |
| $100,000 in sales only (no transaction count) | Several states (e.g., Florida, Pennsylvania) |
| $500,000 in sales | CA, TX, NY (NY also requires more than 100 sales) |
| Varies | Check each state |
States with NO sales tax (5): Oregon, Montana, New Hampshire, Delaware, Alaska (no state sales tax, but some Alaska municipalities levy local sales tax)
Service taxability (varies by state):
| Service | Taxed in Most States? | Example States |
|---|---|---|
| Repair and maintenance (equipment) | Yes (25+ states) | TX, FL, CT, HI |
| Cleaning services (janitorial) | Some (15-20 states) | TX, NM, HI, SD |
| Landscaping | Some (10-15 states) | TX, CT, NM |
| HVAC installation | Varies (often labor exempt, materials taxed) | Most states tax materials separately |
| Consulting | Rarely (5-10 states) | HI, NM, SD, WV |
| Software/SaaS | Increasingly (30+ states) | TX, NY, PA, WA |
| Construction labor | Usually exempt | Most states (but materials are taxed) |
Registration and collection obligations:
- Determine nexus (physical or economic) in each state
- Register for a sales tax permit in each nexus state
- Collect sales tax on taxable sales at the correct rate (state + county + city)
- File sales tax returns on the required schedule (monthly, quarterly, or annually)
- Remit collected taxes to the state
Penalties for not collecting/remitting:
| Penalty | Typical Range |
|---|---|
| Late filing | $50-$250 per return |
| Late payment | 5-25% of tax due |
| Failure to collect | Personal liability for uncollected tax |
| Fraud/willful failure | Criminal penalties in some states |
| Interest | 1-1.5% per month |
The “I didn’t know” problem: If a business should have been collecting sales tax but wasn’t, the business owes the tax (not the customer). The business cannot go back to customers and collect retroactively (in most cases). The liability is the business owner’s.
Voluntary disclosure: most states offer voluntary disclosure agreements (VDA) for businesses that failed to collect. A VDA typically:
- Limits the lookback period (3-4 years instead of unlimited)
- Waives or reduces penalties
- Requires registration and future compliance
How does sales tax apply to small service businesses?
How do I know if I need to collect sales tax?
Sales tax obligations depend on nexus, a connection between your business and a state that triggers a collection requirement. Physical nexus comes from having a location, employee, or inventory in a state. Economic nexus, established after the 2018 Supreme Court decision in South Dakota v. Wayfair, triggers when you exceed a state’s revenue or transaction threshold (each state sets its own figure and period; Florida and Pennsylvania use $100,000 of sales, for example, while California and Texas use $500,000). Each state sets its own rules, rates, and exemptions. If you sell online and ship to multiple states, you likely have economic nexus in several states and must register, collect, and remit sales tax in each.
What is the difference between sales tax and use tax?
Sales tax is collected by the seller at the point of sale and remitted to the state. Use tax is owed by the buyer when sales tax was not collected, typically on out-of-state purchases or items withdrawn from inventory for personal use. As a business, you owe use tax on equipment, supplies, or inventory purchased from vendors who did not charge sales tax. Many states combine sales and use tax on a single return. Failing to self-assess use tax can result in back-tax assessments for the full statute of limitations period, typically three to four years, plus interest and penalties.
Related guides:
Does $120,000 of Texas sales create sales tax nexus?
Not on its own. Texas doesn’t require a remote seller to get a permit until total Texas revenue reaches $500,000 over the preceding twelve calendar months, and that revenue includes taxable and nontaxable sales and sales for resale. So the Florida seller in Scenario 3 is under the Texas line at $120,000.
Pennsylvania is a different story. It uses at least $100,000 of Pennsylvania gross sales in a calendar year, with no transaction count, so $110,000 there does cross it unless some of those sales went through a marketplace that collected the tax. California and New York both use $500,000, and New York also needs more than 100 sales in the prior four sales tax quarters.
Physical presence can change the answer. Texas treats a temporary location in the state, or an employee or representative there who sells or takes orders, as doing business in Texas.
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Yarik Yarosh, CPA. "Small Business Sales Tax: Nexus Rules, Collection Obligations, and Common Mistakes." Blue Cloud CPA, September 5, 2026, updated September 23, 2026. https://bluecloudcpa.com/guides/small-business-sales-tax-nexus-collection-rules
This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.