Sales tax rules for contractors aren’t intuitive. They vary state by state, service-type by service-type, and the contractor’s role often determines whether you pay sales tax to suppliers or charge it to customers. Getting this wrong is a slow-motion accounting disaster.
Sales tax is the compliance topic that produces the most confusion — and rightly so. Rules vary state by state, by contract type, work type, and the structure of the contractor’s billing.
Every state has to answer: when you install materials into a customer’s property, are you the end consumer or a retailer?
Consumer approach (majority of states): Contractor pays sales tax to supplier when buying materials. Doesn’t charge sales tax to customer. States: Texas (many real-property improvements), Florida (many contracts), Georgia, North Carolina, Virginia, Pennsylvania, Illinois, Massachusetts, Ohio.
Retailer approach (some states): Contractor buys materials tax-free using resale certificate. Charges sales tax to customer on materials (sometimes labor). Must register for sales tax permit. States: Arizona, Hawaii, New Mexico (gross receipts), Mississippi, West Virginia.
Hybrid / contract-type (many states): Lump-sum contracts = treated as consumer. Time-and-materials = treated as retailer. States: California, New York, others.
Many states exempt new residential construction from sales tax on labor but tax repair, remodel, and maintenance work — particularly to commercial property. In Texas, new residential construction is generally not subject to sales tax on labor, but remodeling existing structures can be taxable.
Capital improvement: adds value or extends useful life. Repair: maintains or restores existing condition. New roof = capital improvement. Repair to existing roof = repair. In capital-improvement-certificate states (New York), the customer must sign a certificate affirming the work qualifies — that certificate protects the contractor.
In capital-improvement-certificate states (New York is a major example), failing to obtain the signed certificate puts the burden on you to prove the work was capital. If you didn’t get the certificate, you may have to collect and remit sales tax retroactively. Get the certificate.
If you bought something tax-free or out of state and use it in a state that would have charged sales tax, you owe use tax to that state. Bought materials online tax-free? Owe use tax to your home state. Use tax compliance is famously low, but large amounts do get audited.
For any state you work in: (1) Does this state treat contractors as consumers or retailers? (2) If retailer or contract-type: do I need to register for a sales-tax permit? (3) For the work I’m doing: is it taxable in this state? (4) If taxable: do I charge tax on materials only, labor only, or combined invoice? (5) What documentation does this state require?
State sales-tax penalties typically run higher than federal income-tax penalties: unpaid tax + 10–25% penalty + interest at 8–12% annualized + possible negligence/fraud penalties. For a contractor mishandling sales tax for three years on $300,000 of taxable work in a 7% sales-tax state: $21,000 unpaid tax + penalty + interest = $30,000–$40,000.
Identify states where you work. Look up your state’s Department of Revenue contractor publication. Determine which category your state uses. Determine whether your typical work is taxable. If you should have been collecting and remitting and haven’t been, talk to a state tax pro before more time passes.
Foad is a federally licensed Enrolled Agent who writes about tax and bookkeeping for small businesses.