Sales tax on resale items works in two directions, and you handle each one differently. When you buy inventory from a supplier, you pay no sales tax if you give them a valid resale certificate, because the tax will be collected later at the final sale. When you sell those items to end customers, you must collect sales tax and send it to the state in every jurisdiction where your business has a taxable connection. Get the buying side wrong and you overpay; get the selling side wrong and you’re personally on the hook for tax you should have collected but didn’t.
Buying Inventory Tax-Free With a Resale Certificate
A resale certificate is the document that keeps the same product from being taxed twice on its way to the consumer. You present it to your supplier at the time of purchase, and the supplier sells to you without charging sales tax because you’ve certified the goods are for resale, not for your own use. To use one, you need a valid seller’s permit in the state where the purchase happens, and the certificate has to be provided at the transaction, not applied retroactively.
Expiration Periods Vary by State
There is no single national rule for how long a resale certificate stays valid. Some states issue certificates that stay in force indefinitely as long as your business information is current. Others require annual renewal. Others set expiration windows of three to five years. Track renewal dates for each state where you use certificates. Once one lapses, your supplier will start charging tax on your purchases because an expired certificate no longer shields them from liability.
Using the Certificate Only for Actual Resale
Buying something with a resale certificate and then keeping it for personal or business use is tax fraud. States audit for this. The consequences include back taxes on the full purchase price, interest, and substantial penalties.
A related issue catches honest resellers. If you pull an item out of your tax-free inventory to use yourself, whether for product testing, office use, or a giveaway, you owe use tax on it. Use tax is the counterpart to sales tax: it applies when you acquire something tax-free but end up consuming it instead of reselling it. The rate matches your local sales tax rate. If this happens regularly in your business, you need a system for tracking and reporting those conversions.
When You Have to Collect Sales Tax From Your Customers
Your obligation to collect sales tax in a given state turns on whether you have nexus there. Nexus is the legal connection between your business and a state that lets the state require you to collect its tax. Two kinds exist, and either one is enough on its own.
Physical nexus exists when your business has some tangible footprint in the state: an office, a warehouse, a storefront, employees working there. The bar is lower than most sellers expect. Storing inventory in a third-party fulfillment center counts. In some states, even attending a trade show or sending a single sales rep can create it.
Economic nexus exists when your sales into a state cross a dollar or transaction threshold, regardless of any physical presence. The Supreme Court’s 2018 decision in South Dakota v. Wayfair, Inc. cleared the way for this by overruling decades of precedent that had required physical presence.1Supreme Court of the United States. South Dakota v. Wayfair, Inc. The South Dakota law at issue reached sellers delivering more than $100,000 in goods or services into the state, or completing 200 or more separate transactions in a year.
Most states modeled their thresholds on that $100,000 figure, but the specifics aren’t uniform. A few states set higher revenue thresholds of $250,000 or even $500,000. A growing number have dropped the 200-transaction count entirely and look only at revenue. If you sell across state lines, check each state’s current threshold individually.
Which Sales Tax Rate to Charge
Knowing you have nexus is half the answer. You also need the right rate, and that depends on whether the state uses origin-based or destination-based sourcing.
In an origin-based state, you charge the rate where your business is located. Every in-state sale uses the same rate regardless of where the buyer lives. About a dozen states use this approach for in-state sales, including Texas, Ohio, Pennsylvania, and Virginia. It makes compliance considerably simpler.
In a destination-based state, which most states are, you charge the rate at the buyer’s location. That rate can combine state, county, and city taxes, so a single state can have hundreds of possible rates depending on the delivery address. If you sell online into many jurisdictions, tax calculation software is close to essential.
One important wrinkle: even origin-based states switch to destination rules for interstate sales. Ship from Texas to a customer in Georgia and you charge the Georgia rate at the customer’s address, not your Texas rate.
Registering for a Seller’s Permit
Before you collect a single dollar of sales tax, register for a seller’s permit (sometimes called a sales tax permit or certificate of registration) in each state where you have nexus. Collecting sales tax without being registered is illegal and can bring penalties even if you intended to hand the money over.
Registration itself is straightforward. You provide your business name and address, federal EIN or Social Security number, business structure, and estimated sales figures. Most states handle the whole process online, and the majority charge no application fee. A handful require small fees or a refundable security deposit.
If you have nexus in several states, the Streamlined Sales Tax Registration System lets you register in all 24 participating member states through a single free application.2Streamlined Sales Tax. Streamlined Sales Tax Registration System (SSTRS) States outside the agreement require individual registration through their own tax agencies. A seller’s permit is separate from any general business license your city or county requires; you may need both.
Collecting and Remitting What You Owe
On each taxable sale, calculate the applicable rate under the sourcing rules above, add it to the sale price, and show it as a separate line on the receipt. That money belongs to the state from the moment you collect it. You’re holding it in trust until your filing period closes.
States assign filing frequencies based on how much tax you collect. High-volume businesses file monthly, mid-range sellers quarterly, low-volume sellers annually. Due dates vary, but monthly returns are commonly due between the 20th and 25th of the following month. Miss a due date and penalties apply even if the amount owed is zero. Many states charge a minimum flat fee for late-filed returns whether or not you collected anything that period.
On each return, you report total sales, exempt sales, taxable sales, and tax collected. Some states offer a small vendor discount, often between 0.5% and 2.5% of tax collected, as compensation for handling collection and remitting on time. File late and that discount goes away.
Sales to Tax-Exempt Buyers
Not every sale to an end user triggers collection. Government agencies, qualifying nonprofits, and certain other organizations are exempt from sales tax in most states. When you sell to an exempt buyer, collect a valid exemption certificate and keep it on file. Without that documentation, you’re liable for the tax if the state audits the transaction. The burden of proof sits with you as the seller, not with the buyer claiming the exemption.
Selling Through Marketplaces
If you sell through Amazon, eBay, Etsy, or a similar platform, the platform handles sales tax collection and remittance for you in nearly every state. Almost all states with a sales tax have enacted marketplace facilitator laws that shift the collection obligation onto the platform itself.3Streamlined Sales Tax. Marketplace Facilitator
That’s real relief, but it only covers sales made through the marketplace. If you also sell through your own website, at craft fairs, or through any other direct channel, you’re fully responsible for collecting and remitting on those sales. You still need your own seller’s permit as well. The marketplace facilitator law doesn’t eliminate your registration obligation, even if every sale you currently make runs through a platform.
Drop Shipping
Drop shipping creates a three-party puzzle. You take the customer’s order, a third-party supplier ships the product directly to your customer, and the customer never interacts with the supplier. The question is who owes sales tax and to which state.
The retailer, not the drop shipper, is responsible for collecting sales tax from the customer. If you have nexus in the customer’s state, you collect. The complication sits on the wholesale side. When the supplier ships into a state where they have nexus, the supplier may need a resale certificate from you to avoid charging you tax on the wholesale transaction. Without that certificate, the supplier collects tax from you, and you still have to collect from your customer. That creates a double-tax situation you have to resolve later through refund claims.
Getting resale certificates in place before the first shipment is the single most effective way to avoid these tangles. If you drop ship into multiple states, you may need valid certificates on file in each one.
What Non-Compliance Costs
Sales tax isn’t a gray area. States have strong enforcement tools, and the consequences escalate quickly.
Civil penalties for late filing or late payment run roughly 5% to 10% of the tax due per month in most states, with caps that can reach 25% to 35% of the total liability. Interest accrues on top of penalties from the original due date. Filing a zero-dollar return late can still trigger a minimum flat penalty; some states charge $50 or more just for the late filing.
Personal Liability for Owners and Officers
This is where many owners are blindsided. Because sales tax is a trust fund tax, money you collected on behalf of the state, liability doesn’t stop at the business entity. States routinely pursue individuals who had authority over the company’s finances for unremitted sales tax. That covers officers, owners, managing members, and anyone with check-signing authority or control over which bills get paid. The liability survives even if the business closes or files for bankruptcy. Saying you didn’t know about the obligation is almost never a successful defense if you had any role in financial decisions.
Criminal Prosecution
In the worst cases, particularly when a business collects sales tax from customers and pockets it, states bring criminal charges. Prosecutions for sales tax fraud have produced felony convictions and prison sentences. State attorneys general publicize these cases specifically to deter others.
Voluntary Disclosure Agreements
If you realize you should have been collecting sales tax in a state but weren’t, a voluntary disclosure agreement is the way to come forward with reduced consequences. Most states run voluntary disclosure programs, many through the Multistate Tax Commission. The typical deal: you register, file returns, and pay back taxes plus interest for a limited lookback period, commonly 36 to 48 months, and the state waives penalties and doesn’t pursue liability for earlier periods.4Multistate Tax Commission. Lookback Periods for States Participating in National Nexus Program Coming forward voluntarily is almost always a better outcome than being discovered in an audit.
When You May Not Need to Collect at All
Two boundaries are worth knowing. First, five states impose no statewide sales tax: Alaska, Delaware, Montana, New Hampshire, and Oregon.5Tax Foundation. State and Local Sales Tax Rates, 2026 If your business and all your customers sit inside one of these, sales tax collection is largely off your plate. Alaska is the exception within that group because it lets local governments impose their own tax, so sellers in certain Alaska municipalities still have obligations.
Second, most states recognize a casual or occasional sale exemption for isolated, non-recurring transactions. The classic example is a one-time garage sale or a business selling off old office furniture. These exemptions are narrowly drawn and capped by the number of sales or total dollar amount in a year. They don’t apply to businesses regularly engaged in selling goods. If you’re buying inventory with the intent to resell it, you’re operating as a retailer, and the occasional sale exemption won’t shield you from collection.