A seller’s permit number is the ID a state tax agency assigns your business when it registers to collect sales tax, and if you sell taxable goods or services in any of the 45 states with a statewide sales tax, you almost certainly need one. The number identifies your account in the state’s system, obligates you to collect tax from customers and send it to the state on a schedule, and lets you buy inventory from wholesalers without paying tax on it. Registration is usually free and often done online in under half an hour.
What the Number Is
When a state issues the permit, it’s putting your business on the hook as a tax collector. On every taxable sale you add the applicable sales tax to the customer’s total, hold that money, and remit it to the state on a set schedule. The permit number is how the state ties your returns and payments to your account.
It is not your federal Employer Identification Number. The EIN comes from the IRS and covers income tax, payroll, and other federal purposes.1U.S. Small Business Administration. Get Federal and State Tax ID Numbers It is also not a city or county business license, which just grants permission to operate in a municipality. The seller’s permit is specifically about state sales tax.
The name varies by state. California issues a Seller’s Permit, New York a Certificate of Authority, Texas a Sales Tax Permit. You will also see Sales and Use Tax License, Retail License, or Vendor Registration. Different labels, same document.
Who Needs One
If you sell physical goods or taxable services to customers in a sales-tax state, you need to register in that state. That covers storefronts, online shops run from your own website, side operations out of a garage, and temporary setups at flea markets, craft fairs, and pop-ups.
Five states have no statewide sales tax: Alaska, Delaware, Montana, New Hampshire, and Oregon. A business operating only in one of those states does not need a state seller’s permit. Alaska is the caveat, because some local jurisdictions there impose their own sales taxes.
Physical Presence
The traditional trigger is physical presence, what tax authorities call nexus. A storefront, warehouse, office, inventory held in a fulfillment center, or an employee working in a state all create nexus there. Any of those means you register.
Economic Nexus
Since the Supreme Court’s 2018 decision in South Dakota v. Wayfair, states can also require registration based on sales volume alone, with no physical presence at all.2Supreme Court of the United States. South Dakota v. Wayfair, Inc., 585 U.S. ___ (2018) The common threshold is $100,000 in annual sales into a state. Some states also use an alternative threshold of 200 separate transactions, though more than 15 states have dropped the transaction count and look only at the dollar amount.
If you ship to customers in many states, you can trip economic nexus in several at once. Each state where you cross the threshold is a separate registration. Once your sales into any single state approach $100,000, that state’s numbers deserve a close look.
Selling Through a Marketplace
One practical exception saves a lot of online sellers a lot of work. If you sell through Amazon, Etsy, eBay, Walmart Marketplace, or a similar platform, marketplace facilitator laws generally make the platform legally responsible for collecting and remitting sales tax on those orders. Virtually every sales-tax state has adopted these rules.
So if all your sales run through a marketplace that collects for you, you may not need to register in states where the platform is already handling it, and those sales typically don’t count toward your economic nexus threshold. Direct sales are a different matter. If you also sell through your own site or in person, those sales do count, and you’ll need permits wherever your direct volume crosses the threshold.
How to Apply
You apply through the state’s tax agency, which is usually called the Department of Revenue, Department of Taxation, or Comptroller’s office. Most states offer online registration, and the application itself takes 10 to 30 minutes if your information is ready.
The application asks for standard details:
- Your legal structure (sole proprietor, LLC, corporation, partnership)
- Federal EIN, or Social Security Number if you’re a sole proprietor without an EIN
- Business address and any additional sales locations
- Estimated sales volume, which the state uses to set your filing frequency
- Business start date
Most states issue the permit for free. Roughly a dozen charge an application fee, generally $5 to $100, and it’s typically a one-time charge. Online applications are often processed within a few business days and sometimes immediately. Paper applications by mail can take six to eight weeks.
Some states require new applicants to post a security deposit or surety bond before issuing the permit, particularly if there’s a history of tax delinquency or no established credit. The amount is calculated from your estimated monthly tax liability, often somewhere in the range of two to six months of estimated tax, depending on the state.
What the Number Does Day to Day
Two jobs. First, it identifies you when you collect and remit sales tax. Every return you file uses the number to credit your payment to the right account. Second, it lets you buy inventory tax-free from wholesalers and distributors for resale.
When you buy goods you plan to resell, you give your supplier a resale certificate that includes your permit number. The supplier doesn’t charge you sales tax, because the tax will be collected later when you sell the item to the end customer. The certificate must be filled out completely, describe the goods, and state that they’re being bought for resale. Suppliers keep these on file; if a supplier can’t produce a valid certificate during an audit, the state treats the sale as taxable and the supplier owes the tax.
The limit is important. A resale certificate only covers inventory you genuinely intend to resell. Using it to buy office supplies or equipment for your own use means you owe use tax on those purchases, and auditors look for exactly that mistake.
Staying Compliant
The state assigns your filing frequency based on expected tax volume. High-volume businesses file monthly, moderate-volume quarterly, small operations sometimes annually. Returns are due on a set date after each period, and the state expects both the return and the payment by the deadline even if you had zero taxable sales. A forgotten zero-dollar return triggers late-filing penalties just like any other.
Keep detailed records of gross sales, tax collected, resale and exemption certificates you receive, and every return you file. Most states require retention for at least three to four years after the return is filed, and longer if a liability is under review.3Internal Revenue Service. How Long Should I Keep Records In an audit, the burden is on you to prove that a tax-exempt sale was legitimate. No documentation, and the state treats it as taxable.
Penalties
Selling without a required permit is not a technicality states overlook. Consequences include daily fines that add up quickly, back taxes on every sale you should have collected on, interest on the unpaid tax, and criminal prosecution in serious cases. Some states set civil penalties starting at several hundred dollars for the first day and adding more for each additional day.
Even with a permit, late filing or underpayment costs. Late-filing penalties in most states run 5% to 10% of unpaid tax for the first month and escalate from there, with interest accruing shortly after the due date.
The worst position is having collected sales tax from customers and failed to remit it. States treat that money as trust funds belonging to the government, not to the business. That can produce personal liability for owners even when the business is an LLC or corporation.
Renewals, Changes, and Closing
In most states the permit stays valid indefinitely as long as the business is active, with no annual renewal or recurring fee. A few states require periodic renewal; Colorado, for example, renews every two years. Check your state’s rules after you register.
Changes to your legal structure, ownership, or physical location generally require updating the registration or applying for a new permit. Selling or transferring a business doesn’t transfer the permit; the new owner applies for their own.
When you stop selling, close the permit rather than letting it sit. An open permit means the state still expects returns, and if you stop filing, it will eventually assess estimated taxes and penalties. Closing properly means filing a final return through your last day of business, paying any remaining tax, and notifying the tax agency that you’ve ceased operations. Most states allow this online or with a short phone call. One point that catches people out: unsold inventory you bought tax-free with a resale certificate can trigger use tax when you close, because the resale exemption only covers goods you actually resell. Anything you keep, give away, or use personally is taxable at that point.