Quick Answer
Sales tax for online businesses works like this: you collect tax from buyers in states where you have “nexus” (a legal connection), then remit that tax to each state on a regular filing schedule. Most online business owners owe sales tax in 3–10 states once they cross economic nexus thresholds (usually $100,000 in sales or 200 transactions in a state per year). The basic compliance steps: identify nexus → register for permits → configure your platform to collect → file returns by each state’s deadline. Skipping this isn’t a “small business” pass — states actively audit ecommerce sellers now.
If you run an online business — Shopify store, Etsy shop, digital products, services, or some combo — sales tax is probably the topic you most want to avoid. I don’t blame you. The rules are confusing, change constantly, and vary wildly by state. But ignoring sales tax is one of the fastest ways to wreck an otherwise healthy online business.
The 2018 Supreme Court decision South Dakota v. Wayfair fundamentally changed the rules. Before Wayfair, you only had to collect sales tax in states where you had a physical presence. After Wayfair, you can owe tax in any state where you cross a sales threshold — even if you’ve never set foot there.
Let me walk you through everything you need to know, in plain English, so you can build a clean sales tax setup once and stop dreading it forever.
What Is Sales Tax (And Why Do States Care So Much)?
Sales tax is a consumption tax paid by the buyer on retail purchases. As the seller, you’re not paying the tax yourself — you’re collecting it from the buyer and forwarding it to the state. You’re essentially the state’s tax collector for transactions in their jurisdiction.
There are 45 states plus DC that have a state-level sales tax. The five states that don’t are New Hampshire, Oregon, Montana, Alaska (mostly), and Delaware — sometimes called the “NOMAD” states. Local sales taxes (city, county, district) add another layer of complexity, especially in places like California, Colorado, and Louisiana.
State revenue from sales tax has been declining as more commerce moves online, which is why states are aggressive about going after remote sellers. Sales tax compliance for online businesses isn’t optional — it’s enforced.
The Three Conditions That Make a Sale Taxable
For sales tax to apply to a transaction, three things need to be true:
1. You Have Nexus in the Buyer’s State
Nexus is the legal connection between your business and a state. There are two types:
Physical nexus: Triggered by anything that gives you a physical presence — your home/office, employees or contractors, inventory in a warehouse (including Amazon FBA fulfillment centers), trade show attendance, or in-person service delivery.
Economic nexus: Triggered by sales volume. Most states use a threshold of $100,000 in sales OR 200 transactions in the previous 12 months. Cross either one, and you have nexus.
If you don’t have nexus in a state, you don’t collect tax there — even if the buyer lives there.
2. The Product Is Taxable in That State
Tangible goods are taxable in almost every state. But other categories vary:
- Clothing: Exempt in PA, NJ, MN, VT, MA (most), some others. Taxable everywhere else.
- Food: Often exempt or taxed at lower rate.
- Digital products: Taxable in about half of states. Rules change frequently.
- Services: Generally NOT taxable, but a handful of states (HI, NM, SD, WV, CT) tax most services.
- Shipping: Sometimes taxable, sometimes not. Depends on the state and how you invoice it.
3. The Buyer Is Not Exempt
If the buyer is a registered nonprofit, government entity, or business buying for resale, they can provide an exemption certificate. You’re then required to NOT collect tax — but you must keep the certificate on file.
Physical Nexus: Where You Probably Have It Already
Even brand-new online businesses usually have physical nexus in at least one state — their home state. But it’s easy to accidentally create physical nexus in others. Triggers include:
- Home or office location. Where you live and work creates nexus in that state.
- Employees or contractors. A remote employee or regular contractor in another state can trigger nexus there.
- Inventory storage. This is the big one for ecommerce. If you use Amazon FBA, Walmart Fulfillment, or any third-party warehouse, your inventory in their warehouses may give you physical nexus in those states.
- Drop-shipping arrangements. Depending on the state, your drop-shipper’s location can create nexus for you.
- Trade shows, pop-ups, and craft fairs. Even a few days a year can trigger nexus in some states.
- Click-through nexus. A few states (NY, CA) treat affiliate relationships as creating nexus.
If you use Amazon FBA, request an inventory location report. You may be storing in 15+ states. That’s 15+ potential physical nexus filings, regardless of sales volume.
Economic Nexus: The Wayfair Threshold
For online businesses, economic nexus is the bigger trap. The basic rule: cross a state’s sales threshold and you have to register and collect.
The most common threshold is $100,000 in sales OR 200 transactions in a state in the previous 12 months. But there are variations:
- California, Texas, New York: $500,000 in sales (no transaction threshold).
- Tennessee: $100,000 in sales (no transaction threshold).
- Kansas: $100,000 in sales (no transaction threshold; changed 2024).
- No threshold states: Most no-sales-tax states (Alaska local jurisdictions sometimes do have rules).
The transaction threshold catches a lot of low-priced product sellers off guard. If you sell $25 digital templates and have 250 buyers in Iowa? That’s nexus, even though you only made $6,250 in that state.
The Sales Tax Compliance Workflow (Step-by-Step)
Here’s the practical process I walk every new client through:
Step 1: Pull a Sales-by-State Report
Get a 12-month report from your platform (Shopify, WooCommerce, Etsy, Stripe, etc.) showing total sales and transaction count by state. This is your starting point.
Step 2: Identify Your Nexus States
For each state, check whether you’ve crossed the economic nexus threshold. Add any states where you have physical nexus (home, FBA inventory, contractors, etc.). This is your “nexus list.”
Step 3: Determine Product Taxability
For each state on your nexus list, determine whether what you sell is actually taxable there. A clothing seller in Pennsylvania may have nexus but no tax obligation (clothing is exempt in PA).
Step 4: Register for Sales Tax Permits
Apply for a sales tax permit (sometimes called a “seller’s permit” or “vendor’s license”) in each state where you owe tax. Most states process applications online in 1–2 weeks. Fees range from free to about $50.
If you’re registering in multiple Streamlined Sales Tax (SST) states, use the SST Registration System — one form for 24 states.
Step 5: Configure Your Platform to Collect Tax
Set up tax collection in your ecommerce platform. Most modern platforms (Shopify, BigCommerce, WooCommerce, Squarespace) can either calculate tax automatically or integrate with a tax engine like TaxJar or Avalara that handles rates.
Important: collecting tax without a permit is illegal in most states. Don’t turn on collection until your permit is approved.
Step 6: File Sales Tax Returns
Each state assigns you a filing frequency: monthly, quarterly, or annually. Higher sales volume usually means more frequent filing. Each return is due by a specific date — typically the 20th of the month following the filing period.
You file a return even when you owe $0. Skipping a “zero return” is one of the most common ways small sellers rack up penalties.
Step 7: Track and Reassess Quarterly
Nexus is a moving target. New states will cross threshold as your business grows. Reassess every quarter and add new states to your collection scheme.
Marketplace Facilitator Laws: The Plot Twist
If you sell on Amazon, Etsy, eBay, Walmart, or similar marketplaces, here’s good news: those platforms collect and remit sales tax on your behalf in most states. This is because of “marketplace facilitator” laws, which shift the collection responsibility from individual sellers to the marketplace.
But — and this is important — those marketplace sales STILL count toward your economic nexus threshold in many states. Just because Amazon is collecting tax on your Wisconsin sales doesn’t mean Wisconsin sales don’t trigger nexus for your Shopify store too.
Some states (like California and Tennessee) explicitly exclude marketplace sales from nexus calculations. Others (like Pennsylvania) count them. Always check state-by-state.
Also: marketplace facilitator coverage isn’t 100%. Etsy, for instance, doesn’t collect tax in every jurisdiction. Always verify your platform’s coverage before assuming you’re covered.
Common Sales Tax Mistakes Online Sellers Make
These come up over and over in my work:
Mistake 1: Collecting tax without being registered. This is illegal. Register first, collect second.
Mistake 2: Charging the wrong rate. Sales tax includes state, county, city, and sometimes district rates. Manual rates almost always get this wrong. Use a calculator like TaxJar or Avalara.
Mistake 3: Only filing in your home state. If you’ve crossed nexus in other states, you need to file there too.
Mistake 4: Skipping zero-return filings. Even if you owed $0 in a state during a filing period, you typically have to submit a return. Skipping it triggers penalties.
Mistake 5: Treating sales tax money as revenue. The tax you collect isn’t your money. It’s the state’s money you’re holding in trust. Keep it in a separate bank account or at least separate it on your books.
Mistake 6: Waiting until “next year” to deal with it. Sales tax compounds. Every month you ignore it means more unfiled returns, more states crossed, and bigger penalties when you eventually catch up.
Mistake 7: Assuming your accountant is handling it. Most general bookkeepers and tax preparers do NOT handle sales tax. You need a sales tax specialist or a service like TaxJar AutoFile.
What If You’ve Been Out of Compliance?
If you’re reading this and realizing you’ve been selling for years without addressing sales tax, here’s the good news: you have options.
Voluntary Disclosure Agreements (VDAs). Most states offer VDAs where you self-report uncollected tax in exchange for reduced penalties and a limited lookback period (usually 3–4 years instead of unlimited). VDAs are typically the cleanest way to get current.
Amnesty programs. Some states run periodic amnesty programs where penalties are waived if you come forward and pay back tax. These are state-specific and time-limited.
State-by-state cleanup. For some sellers, it makes sense to register going forward and only address the past in states where the exposure is large.
A sales tax specialist can help you triage which states need a VDA, which need just forward-going registration, and which can be safely ignored due to low exposure.
Sales Tax FAQ for Online Businesses
Do I need a sales tax permit in every state?
No — only in states where you have nexus and sell taxable products. Most small online businesses have nexus in 1–10 states, not 50.
How do I know my nexus thresholds?
Sales-tax.com, TaxJar, and Avalara all maintain free state-by-state threshold lookup tools. Bookmark one and check quarterly.
How much do sales tax services cost?
For a small online business, expect $300–$1,500/year for software like TaxJar AutoFile or Avalara TrustFile. Specialist consulting is usually $150–$400/hour. Compared to penalties for noncompliance, both are usually worth it.
Do I owe sales tax on international sales?
No, US sales tax doesn’t apply to non-US buyers. But you may owe VAT (in the EU/UK), GST (in Canada/Australia/New Zealand), or similar consumption taxes in the buyer’s country. International sales tax is a separate (and complex) topic.
What’s the difference between sales tax and income tax?
Income tax is paid on your business’s profit, by you, to the IRS and your state. Sales tax is collected from buyers and forwarded to states. They’re completely separate.
Can I just include the sales tax in my listed price?
In most states, you have to show sales tax as a separate line item — not bundled into the price. A few states allow “tax-inclusive” pricing if you disclose it. Check your state’s rules.
What if I sell only to other businesses (B2B)?
You may not owe sales tax if your B2B buyers are buying for resale and provide exemption certificates. But you still need to be registered and collect those certificates. B2B sellers aren’t automatically exempt — they just have different compliance rules.
Should I form an LLC to handle sales tax?
Your entity type (LLC, S-corp, sole prop) doesn’t change your sales tax obligations. Sales tax is based on your business activity, not your legal structure.
Your Next Step
Sales tax is one of those topics where putting it off costs you significantly more than addressing it. The earlier you get a clean setup, the less it costs you in penalties, time, and headaches.
If you want to handle this yourself, my [Online Business Sales Tax Toolkit] gives you a state-by-state nexus tracker, a registration checklist, platform configuration guides for Shopify/WooCommerce/Squarespace, and a filing calendar template.
If you’d rather hand it off to someone who deals with this every day, I work with online business owners to assess nexus exposure, file Voluntary Disclosure Agreements where needed, and set up clean ongoing collection that runs on autopilot. [Book a free Sales Tax Discovery Call] and I’ll tell you straight whether you need help and what the cleanest path forward looks like.
You started your online business to serve customers — not to become an unpaid tax collector. Let’s build a system that handles this in the background so you can focus on growing.
Tax Disclaimer: This post is for educational purposes only and is not tax advice. Sales tax rules change frequently and vary significantly by state. Always consult a qualified tax professional before making decisions about sales tax registration or filing.