Resale certificate and sales tax exemption certificate guide

It's 6:30 in the morning, the coffee at the counter is still too hot to drink, and a contractor you've known for years slides a piece of paper across the counter at your lumber yard or paint store and says he's buying this load for resale. Do you take it? The fair answer is that it depends, and most of what it depends on is you. A resale certificate or exemption certificate moves the sales tax responsibility off that transaction only when your store does its part: you take a complete certificate at the time of sale, you check that what the customer is buying fits the business named on the paper, you verify the number where your state offers a lookup, and you file the certificate somewhere an auditor (and your next cashier) can find it. Get those four habits right and the certificate is your shield, but get them wrong and the paper is decoration, because when the certificate fails, the store owes the tax.

Resale certificate vs. exemption certificate

The two documents get used interchangeably at the counter, and they shouldn't be. A resale certificate says the buyer is purchasing the item in order to resell it, so the tax gets collected later, when the item reaches the final consumer. An exemption certificate says the buyer or the use itself is exempt from tax: a nonprofit, a school, a government agency, a manufacturer buying ingredients for a product, or a farm buying qualifying supplies. Farm and ag exemptions are their own world with their own forms and their own traps, so we wrote a companion guide to farm and ag exemptions at the counter and won't repeat it here.

Either way, the certificate only does its job if the seller takes it properly, and "properly" is defined state by state, which is where things get interesting.

Contractors are not all resellers: state rules differ

Contractors are the trickiest customers at your counter because many states treat a contractor who installs materials into real property as the consumer of those materials, not a reseller of them. That framing sounds like semantics until an auditor reads it as "you owed tax on that pallet of joist hangers."

Texas draws the line by contract type, and the Texas Comptroller's Publication 94-116 is plain about it: "Under a lump-sum contract, you pay tax on all your supplies, materials, equipment, and taxable services when you buy them. You don't charge your customer tax." But flip the contract structure and the answer flips with it: "Under a separated contract, you give your suppliers resale certificates instead of paying tax on materials you incorporate into the customer's real property." Same contractor, same 2x4s, different paperwork, different answer.

Florida starts from the consumer position too. The Department of Revenue's brochure GT-800007 says that for "lump sum, cost plus or fixed fee, guaranteed price, or time and materials contracts ... the contractor is the final consumer of materials and supplies used in performing the contract." The exception is the retail sale plus installation contract, where the materials are "specifically described and itemized" on the contract with the owner. In that case the contractor is selling the materials to the owner and may use a Florida Annual Resale Certificate to buy them from you.

Some states are blunter. The state notes attached to the MTC Uniform Resale Certificate (revised October 14, 2022) say of Kansas: "This resale certificate may not be used by contractors to purchase materials without sales tax." Nevada's note warns that "Contractors are generally considered consumers of tangible personal property pursuant to NAC 372.200 and are unable and should not use this certificate, and Sellers should not accept it from a contractor." North Carolina's says the certificate "is not valid as an exemption certificate if signed by a person such as a contractor who intends to use the property."

So a contractor's resale certificate is valid in some situations and invalid in others, and the answer depends on the state and on the contract the contractor is working under. If a regular asks you to take his word for it, the kind answer is: show me the contract type, and let's check what our state says.

The multistate forms: Streamlined and MTC

Two forms cover a lot of ground if you sell to buyers who are registered in more than one state. The Streamlined Sales Tax Certificate of Exemption works in all Streamlined member states, which run from Arkansas and Georgia out to Washington, West Virginia and Wyoming, with Tennessee participating as an associate member, and it can be provided in paper or electronic form. The Streamlined program also offers sellers real protection: per the program's FAQ, "States no longer punish the seller when they sell something tax exempt to a purchaser that provided a completed exemption certificate, presuming the seller did not solicit an improper exemption and no fraud was involved."

The MTC Uniform Sales & Use Tax Resale Certificate is the other workhorse: 36 states have indicated it can be used as a resale certificate, and the form was updated October 14, 2022. But the MTC itself adds the caution that matters: "For information regarding whether the certificate will be accepted in the applicable state, you should talk to the revenue department of that state." A multistate form is a starting point, not a hall pass. The state where the sale happens decides what it accepts.

How to verify a certificate before you accept it

A permit number scribbled on an invoice is not a certificate. Texas says it outright in its resale certificate FAQ: "The customer's sales tax permit number or a copy of the customer's permit is not a substitute for a resale certificate and does not relieve a seller's responsibility for collecting sales tax." You need the completed form, and where the state offers a lookup, a quick check that the number is live.

Illinois deserves its own sentence. Per the MTC state notes, "'Good faith' is not the standard of care to be exercised by a retailer in Illinois. A retailer in Illinois is not required to determine whether the purchaser actually intends to resell the item. Instead, a retailer must confirm that the purchaser has a valid registration or resale number at the time of purchase." In most states you're judging whether the purchase fits the business; in Illinois you're confirming the number. Florida sweetens the verification habit: a seller who accepts a copy of the certificate "will not be held liable for tax on the transaction if it is later determined the purchaser was not an active, registered dealer at the time of the transaction," and GT-800060 tells you to "Keep a record of all verification response reports to document your tax-exempt sales."

Good faith, expiry and renewal

Good faith is the phrase that decides most disputes, and it comes down to whether the purchase fits the buyer's business. The MTC's general note puts it this way: "In order for the certificate to be accepted in good faith by the Seller, Seller must exercise care that the property or service being sold is of a type normally sold wholesale, resold, leased, rented or incorporated as an ingredient or component of a product manufactured by Buyer and then resold in the usual course of its business." Florida gives the example every counter manager should memorize: "a resale certificate from a car dealership should not be accepted for the purchase of office supplies or similar items not normally sold by car dealerships." The paint store version is a landscaping company trying to buy cabinet enamel on a resale certificate. You know your customers, and that knowledge is part of the standard.

Certificates also age, differently by state. Florida's Annual Resale Certificates expire every year on December 31, per GT-800060. Tennessee goes the other direction: per the Department of Revenue's Sales Tax Exemptions workshop (April 28, 2026), "The certificates of resale do not have an expiration date; however, vendors may request a recent copy," and each location needs its own certificate. Illinois, in the MTC state notes, says blanket certificates "should be updated periodically, and no less frequently than every three years." Iowa's Form 31-014 instructions (September 8, 2025) say a blanket certificate "remains effective until canceled by the purchaser or until 12 months have elapsed with no purchases between the same purchaser and seller," and that the certificate "must be completed and be in effect within 90 days of the date of sale." The practical takeaway: put a fresh-copy request into your annual rhythm, because your customer's certificate may have quietly lapsed while you weren't looking.

Where audits bite

Auditors don't go looking for drama; they go looking for gaps. The certificates that fail are the incomplete ones (California's Publication 103 lists what a valid certificate needs: business name and address, seller's permit number or the reason none is required, a description of the property, a statement that it's purchased "for resale," the date, and a signature), the ones collected after the fact, the ones where the items don't match the business, and the ones nobody can find. Texas requires sellers to "retain the resale certificates in your records (for four years)," per the Comptroller's FAQ. And the consequence is the same everywhere: as Kentucky's Farm Exemption Certificate warns, "Sellers failing to obtain a completed certificate will be held liable for the sales and use tax." When the paper fails, the seller owes the tax. Florida reminds sellers that resale fraud "is a third-degree felony subject to a 200% penalty," which is aimed at the buyer but tells you how seriously the state takes the paper.

A paint store in New York told us about the after-the-fact version of this problem: a contractor's customer received a tax-exempt certificate partway through a project, after invoices had already gone out with tax charged, and asked the store to fix the old invoices. The rework was significant, and every corrected invoice was a small audit trail of its own. Collecting the certificate before the first sale on the account is far cheaper than fixing invoices after it.

Keeping certificates attached to the customer account

The four habits from the top of this article are mostly a filing problem wearing a tax costume. Your POS should hold the exemption on the customer account rather than in a drawer, attach the document itself to that account, and make the exempt sale the easy path at checkout instead of a manager override with a key. Here's how we handle it in Rundoo, and what stays on your plate.

A customer's tax exemption lives on the customer account, where you record the exemption ID from their certificate, and you can attach a scan or a phone photo of the certificate to the customer's file, including from the mobile app, so the paper is on hand when an auditor asks. Rundoo records the exemption number but does not validate it against a state database, so the lookups in the table above stay your job. A cashier with the right permission can set a single sale to tax exempt at checkout when a customer presents a certificate, and a completed sale is final: to change the tax on a finished invoice you refund it and check the customer out again, which is one more reason to collect the certificate before the sale instead of after.

The mixed-customer problem has a clean answer too. The same New York store asked us how to handle one customer with both taxable and tax-exempt projects, and the fix is structure, not memory: a customer can have separate jobs, and a job can be tax exempt, so one contractor's exempt school project and taxable kitchen remodel stay on the same account without mixing. The product can carry the tax status as well: an item can be marked single-use non-taxable, so an exemption applies to the qualifying items and not the rest of the ticket, while a blanket exemption number exempts everything, which suits schools, churches and government buyers. And because these accounts tend to carry pricing tiers, credit limits, statements and aging alongside the tax status, everything the counter needs about a contractor lives in one place. When a store switches to Rundoo, the tax-exempt IDs migrate with the customer accounts, which our data migration guide covers in detail. Whether you run a hardware store, a paint store or a lumber yard, the goal is the same: the certificate follows the customer, not the cashier's memory.

The counter habit that pays

None of this is hard, and all of it is habit, so take the complete certificate at the time of sale, check that the cart fits the business on the paper, verify the number where your state offers a lookup, and keep the document where the next person can find it. Do that, and tax-exempt sales stop being a leap of faith and become what they should be: certifiably routine.