US sales tax compliance means collecting the right tax in every state where you have an obligation, then filing and remitting it on time. Forty-five states plus the District of Columbia (DC) levy a statewide sales tax, and each writes its own rules, according to the Tax Foundation’s 2026 sales tax data. One missed registration can create years of back-tax liability.
This guide walks the full path: nexus, registration, rate collection, exemption certificates, filing, remittance, use tax, and audits. If you run an online store or an early-stage company, pair it with our sales tax compliance guide for startups.
What Is US Sales Tax Compliance?
Sales tax compliance means collecting, filing, and remitting state and local sales tax everywhere your business has nexus. The United States has no federal sales tax. Each state sets its own rates, rules, and exemptions. Forty-five states plus DC tax sales; five do not.
The five states with no statewide sales tax form the acronym NOMAD: New Hampshire, Oregon, Montana, Alaska, and Delaware, per the Tax Foundation. Alaska is the exception you cannot ignore. It has no statewide tax, but its local governments levy their own, and more than 100 Alaska jurisdictions do, according to the Alaska Remote Seller Sales Tax Commission (ARSSTC). Oregon sits at the other end with a 0% general sales tax, per the Oregon Department of Revenue.
Rates run high elsewhere. California levies the highest statewide base rate at 7.25%, per the California Department of Tax and Fee Administration (CDTFA). Local rates stack on top of that. An estimated 30,000 local jurisdictions have legal authority to impose their own sales tax, according to the U.S. Government Accountability Office (GAO).
What Does the Step-by-Step Sales Tax Compliance Process Look Like?
Sales tax compliance follows seven steps: determine nexus, register for permits, collect the right rate, manage exemption certificates, file returns, remit payment, and keep audit-ready records. Work them in order for every state where you sell. The checklist below is your roadmap, and each step gets its own section further down.
- Determine where you have nexus (physical or economic).
- Register for a permit in each nexus state before collecting.
- Collect the correct combined rate for the delivery location at checkout.
- Manage exemption certificates for every tax-free sale.
- File returns on each state’s assigned schedule.
- Remit the tax you collected by the due date.
- Keep audit-ready records and monitor rule changes.
What Is Sales Tax Nexus?
Sales tax nexus is the connection between your business and a state that triggers a duty to collect that state’s sales tax. Two kinds create it: physical nexus and economic nexus. You can have nexus in many states at once. Each state defines its own triggers.
What Is Physical Nexus?
Physical nexus comes from a tangible connection to a state. Offices, stores, warehouses, and stored inventory all create it. So do employees, contractors, and traveling sales reps. Inventory held in a state through Fulfillment by Amazon (FBA) or a third-party logistics (3PL) provider counts too, even when you never set foot there.
What Is Economic Nexus?
Economic nexus lets a state require sales tax collection based on sales volume alone, with no physical presence. The 2018 Supreme Court decision South Dakota v. Wayfair, Inc. overturned the old physical-presence rule from Quill Corp. v. North Dakota. States can now tax remote sellers who cross a dollar or transaction threshold.
South Dakota’s original test, the model upheld in Wayfair, was $100,000 in sales or 200 transactions. The trend since has been to drop the transaction count. South Dakota itself repealed the 200-transaction prong effective July 1, 2023, leaving only the $100,000 sales threshold, per the South Dakota Department of Revenue.
What Are the Economic Nexus Thresholds by State?
Most states set economic nexus at $100,000 in sales. Some use higher dollar thresholds, and a few still keep a transaction-count test. Re-verify every threshold below against the state Department of Revenue (DOR) before you rely on it, because states change these rules often. See Commenda’s US nexus exposure guide for the full, current list.
| State | Economic nexus threshold | Key detail | Source |
|---|---|---|---|
| South Dakota | $100,000 in gross sales | 200-transaction test repealed July 1, 2023 | South Dakota DOR |
| California | $500,000 in sales | High-tier dollar threshold, no transaction count | CDTFA |
| Texas | $500,000 in Texas revenue | Rolling 12 months, no transaction count | Texas Comptroller |
| New York | $500,000 in gross receipts AND 100+ sales | Both conditions required | New York DOR |
| Alaska (local) | $100,000 in statewide gross sales | 200-transaction test repealed Jan 1, 2025 | ARSSTC |
How Do You Register for a Sales Tax Permit?
Register with each state’s Department of Revenue before you collect a cent. Most states offer free or low-cost online registration and issue a permit in days to a few weeks. Collecting sales tax without a permit is illegal in most states. A compliant sales tax license is a permit validly issued, active in every state where you have nexus, and kept current with filings.
Timelines vary by state. In Texas, remote sellers must register once they exceed $500,000 in Texas revenue over the preceding 12 months, no later than the first day of the fourth month after crossing it, per the Texas Comptroller.
What Documents Do You Need to Register?
You need core business and tax details ready before you start the application. Most states ask for the same set of items, listed below. Gather them first to avoid a stalled registration.
| Document | What it is |
|---|---|
| EIN or TIN | Employer Identification Number or Taxpayer Identification Number |
| Formation documents | Articles of incorporation or organization |
| Officer/owner information | Names, addresses, and IDs of responsible parties |
| NAICS code | North American Industry Classification System code for your business |
| Bank details | Account used for remittance |
| Estimated sales | Projected taxable sales in the state |
| Nexus start date | The date your obligation began |
When Should You Register?
Register when you cross a state’s threshold, open a physical location, or start selling taxable goods there. Do not wait. Some states require registration by the next transaction after you cross the threshold. For example, once your Texas revenue tops $500,000 in a rolling 12-month window, the Texas Comptroller requires registration by the first day of the fourth month after.
How Do You Collect the Right Sales Tax Rate?
Charge the combined state, county, city, and district rate for the delivery location at the point of sale. Most states use destination-based sourcing, so the buyer’s location sets the rate. A few origin-based states use the seller’s location instead. Getting the rooftop-accurate rate right is the core of collection.
Local taxes stack fast. In California, voter-approved district taxes of 0.10% to 2.00% sit on top of the 7.25% base rate and apply in areas covering more than three-fourths of all California businesses, per the CDTFA. Product taxability also varies by state. Clothing, for example, is fully taxable in many states, exempt in some, and taxed only above a set price in others. Confirm each product category with the state DOR.
How Do Exemption Certificates Work?
An exemption certificate is the document a buyer gives you to purchase without tax, such as for resale or nonprofit use. Collect and store a valid certificate for every exempt sale. Without one, you owe the tax yourself if an auditor reviews the sale, not the buyer.
Common types cover resale, nonprofit, government, and manufacturing purchases. Validate each certificate at the time of sale, not after. Expiration and renewal rules vary by state, and some require an annual refresh. Multistate forms exist too, including Streamlined Sales Tax (SST) and Multistate Tax Commission (MTC) certificates. Learn the details in our sales tax exemption certificates guide.
How Do You File and Remit Sales Tax?
File a return and remit the tax you collected to each state by its due date. States assign monthly, quarterly, or annual filing based on your volume. Higher volume means more frequent filing. Filing and remitting are separate steps: filing reports the tax, remitting pays it. Both must be on time.
Once registered, you must file even in periods with zero sales, or you still face penalties. Many states set the due date on the 20th of the month after the period. Large filers in some states must make accelerated prepayments. Amendments are allowed through each state’s correction process. The New York example below shows how penalties stack; see our guide on how to remit sales tax and track deadlines with the Commenda compliance calendar.
| Penalty (New York) | Amount | Source |
|---|---|---|
| Late-filed return with tax due | 10% of tax due for the first month, plus 1% per additional month | New York DOR |
| Maximum late-filing penalty | Capped at 30% of tax due | New York DOR |
| Minimum late-filing penalty | Not less than $50 | New York DOR |
What Is Use Tax and When Does Your Business Owe It?
Use tax is the self-assessed twin of sales tax. You owe it when you buy taxable goods without paying sales tax, then use them in a taxing state. A classic example is out-of-state equipment bought tax-free. The rate usually mirrors the sales tax rate for the location.
There are two forms. Consumer use tax applies when a business or individual self-assesses tax on untaxed purchases. Seller use tax applies when a remote seller collects on out-of-state sales. Businesses report and pay use tax on the same state returns as sales tax. See the sales and use tax forms guide for filing details.
How Does Sales Tax Compliance Work for Ecommerce Businesses?
Marketplace facilitator laws make platforms like Amazon and Etsy collect and remit sales tax on marketplace orders in every sales-tax state. You still own your direct-channel sales, your registrations, and your returns. Marketplace sales often still count toward your nexus thresholds, depending on the state.
Two rules trip up online sellers. Digital goods taxability varies: some states tax software and streaming, others exempt them, so map each product code carefully. Shipping taxability varies too, and often turns on whether you state the charge separately. Confirm both with the relevant state DOR before you configure checkout.
How Do Multi-State Sellers Manage Sales Tax Compliance?
Multi-state sellers track nexus in every state, register where they cross thresholds, and manage each state’s rates, rules, and filing calendar. Review your sales by state at least quarterly. Register where you have real exposure, and avoid registering where you do not.
Over-registration costs real money in filing fees and zero returns. Under-registration risks back tax, penalties, and interest. The Streamlined Sales Tax (SST) program offers free registration and simplified filing across its member states as one way to cut the workload. Our sales tax compliance guide for multi-state businesses covers the cadence in depth.
What Happens in a Sales Tax Audit?
In a sales tax audit, the state reviews your returns, exemption certificates, and sales records, then assesses tax, penalties, and interest on any gaps. Common triggers include missing exemption certificates, nexus without registration, and third-party data matching. Auditors also check use tax on your own purchases.
Keep records for the full statute of limitations, typically three to four years, though some states require longer. Confirm the retention period with each state DOR. Auditors request invoices, resale and exemption certificates, filed returns, remittance proof, and transaction data by jurisdiction. Clean, complete records are your best defense.
When Should You Automate Sales Tax Compliance?
Automate once you have nexus in more than two or three states or sell across multiple channels. Manual rate lookups and filing calendars stop scaling fast. Sales tax compliance software tracks physical and economic nexus exposure, applies rooftop-accurate rates at checkout, manages exemption certificates, and files and remits for you.
A US-only seller with a single sales channel may be adequately served by a point solution. Beyond that, automation earns its place. Commenda supports 100+ Enterprise Resource Planning (ERP) systems, APIs, and custom integrations, so tax calculation fits your existing checkout and accounting stack.
How Commenda Automates US Sales Tax Compliance
Commenda’s indirect tax software tracks your physical and economic nexus across all states, calculates rooftop-accurate rates at checkout, and handles registration, filing, and remittance. It manages your exemption certificates and keeps your filing calendar current, so a missed threshold or deadline stops keeping you up at night.
Check your exposure with the evergreen US nexus exposure guide for thresholds, and look up any rate with the Commenda sales tax calculator. Book a demo to get a free nexus exposure assessment across every state you sell into.
