Materials, labor, and who owes the sales tax

Before pricing installed materials, check tax on both your purchases and the work you sell. Consumer or retailer treatment affects material tax, but paying a supplier does not automatically make the customer's bill tax-free. The state, work and contract type determine the obligations and any available credits.

Consumer and retailer treatment of installed materials

Consumer and retailer rules describe how the state treats materials you buy and install. They do not, by themselves, decide whether your service is taxable.

Consumer treatment. You generally pay tax when buying materials you consume in the work, or owe use tax if the seller did not collect it. Include nonrefundable purchase tax in your job cost. Whether the finished work also carries sales tax is a separate check.

Retailer treatment. Where you resell materials and qualify to buy them tax-free using a resale certificate, you generally collect tax on the taxable selling amount, including markup. The applicable rule determines whether labor or other charges are also taxable.

Purchase tax and service tax can both apply. Under New York's repair and maintenance rules, contractors generally pay tax on building materials and charge tax on the total taxable repair service. A registered contractor can claim an eligible material-tax credit for materials transferred to the customer, with supporting records. The same credit does not generally apply to materials used in capital improvements or tools kept by the contractor.

Check labor taxability, certificate requirements and locality sourcing alongside material treatment.

In some states, how you write the contract decides it

A fair number of states do not answer this once. They answer it per contract.

The distinction is usually lump-sum versus separated. A lump-sum contract quotes one price for the finished work. A separated contract shows materials and labor as separate amounts to the customer; it can still have a fixed total price. In several states that formatting choice moves you between the two models: lump-sum makes you the consumer, separated makes you the retailer of the materials.

For Texas new construction and residential repairs or remodeling, this distinction matters. The Comptroller's guidance for contractors (publication 94-116, which sits on top of Rule 3.291) walks through both. Nonresidential repair and remodeling generally has different rules: the total charge is taxable. Do not use the residential labor treatment for a commercial remodel.

In other states, how you write the contract changes nothing.

• Generally a consumer. Pennsylvania's construction regulation generally taxes the contractor's purchase of materials installed in real property. Specific exemptions can apply; this does not decide tax on separate retail sales.
• Neither model. Arizona does not levy a conventional sales tax at all. It taxes the privilege of doing business, and construction has its own classification, assessed on project receipts with a statutory standard deduction standing in for labor — and separate treatment again for maintenance, repair, replacement and alteration work. Use the Arizona Department of Revenue's contracting guidance for the applicable classification and deductions. A rule of thumb carried in from another state is worse than useless here.

One job, priced under both rules

Illustrative residential job: $900 of material cost and $1,500 of labor before material markup. Assume the consumer contract has no tax on the finished work, while the retailer contract taxes only material sales. Materials get a 30% markup, and both purchase and customer sales use a fictional 7% rate. These assumptions let us compare consumer and retailer treatment; they are not universal state rules.

Under these assumptions the customer totals match: applying the same tax rate before or after the same percentage markup gives the same result. Different purchase and sale tax rates or taxable labor can change that result.

Use tax can apply when you use taxable goods and the seller did not collect sufficient tax, including some out-of-state purchases or stock bought for resale but later consumed. Out-of-state suppliers can collect tax. Check your state's rules and credits for tax already paid; Pennsylvania's use-tax guidance gives one example.

Getting it wrong is expensive in both directions

Leaving nonrefundable purchase tax out of cost. In the consumer example above, marking up $900 instead of the full $963 produces a $2,670 bid. That is $81.90 below the $2,751.90 price calculated from the tax-inclusive cost and chosen markup. Check whether purchase tax is a final cost or an eligible credit before applying your margin.

Buying on a resale certificate without the required tax treatment. If you consume the materials, use tax may apply to your cost. If you make a taxable retail sale, sales tax may be due on the selling amount. Determine which obligation applies before correcting the return.

Collecting tax you did not owe. Ask the revenue department how to remit or refund it. Do not treat amounts labeled sales tax as extra business income.

Where your state answers this

Most states with a sales tax publish a bulletin written specifically for construction contractors. That is the document you want, not the general sales tax guide, and you should take the current edition from the agency's own site. If your work straddles categories — you sell and install appliances as well as remodel, or you fabricate before you install — ask for a written determination on your own facts and keep it. Ask again before your first job across a state line — the answer you have is your own state's, and the next state may have picked the other model.

Price from the cost you actually paid

If you are the consumer, include nonrefundable purchase tax in your material cost before calculating the selling price. Do that calculation in your costing sheet, then save the selling price in DoneQuote. Review the quote lines before sending; carry the approved figures into your invoicing tool.

If the applicable rule treats you as a retailer and exempts labor, keep materials and labor separately stated where required and apply tax to the correct selling amounts.