Sales tax for contractors, without the headache

Sales tax is straightforward for a shop. You sell a thing, you collect tax on it, you send the tax on.

Contractors are treated differently, and the difference is where the confusion starts. You are not usually reselling material to your customer. You are using it to improve their property — and most states have decided that makes you the end consumer of that material, not a retailer.

The idea that explains most of it

In many states, a contractor doing work on real property is treated as the consumer of the materials they install.

That means you pay sales tax when you buy the material from your supplier. You then generally do not charge your customer separate sales tax on it — the tax has already been paid, and its cost is simply part of what you bill.

This is why the sales tax question feels different for you than for a retailer, and why advice written for shops does not transfer.

Where it stops being simple

Three things complicate it, and all three vary by state.

Real property versus tangible personal property. Installing a system that becomes part of the building is usually treated differently from selling equipment that stays movable. Replacing a rooftop unit and selling a portable heater are not necessarily the same transaction.

Repair and service labour. Some states tax certain services, some do not, and several tax repair labour while exempting new construction. The same job can be treated differently depending on which side of that line it falls.

The customer. Work for an exempt organisation, or on certain public projects, may allow you to buy material tax-free with the right certificate — but only with the certificate, held before the purchase.

There are also states that treat contractors as retailers rather than consumers, where you buy material for resale and charge tax on the job. If you work across state lines, you may be in both worlds at once.

What this means for your books

You do not need to be an expert on your state's rules to keep records that make compliance easy. You need three things.

Sales tax paid on purchases coded consistently. If you are a consumer of materials, that tax is part of your material cost and belongs with it. Buried inconsistently, your job costing is wrong and your material spend is unclear.

Sales tax collected coded to a liability account, never to income. Tax you collect is not revenue — it is money you are holding for the state. In income it inflates your revenue, overstates your profit and produces a wrong tax return.

Separate tracking per state, if you work in more than one. Filings are per state, and a single combined figure has to be unpicked before anything can be filed.

Get those right and preparing a return is a report rather than an investigation.

Working across state lines

This is where contractors most often get caught, usually by accident.

Taking work in a neighbouring state can create obligations there — registration, filing, and potentially tax on that work — under rules that differ from your home state. Contractors frequently do a handful of out-of-state jobs without realising anything changed.

If you cross state lines, even occasionally, it is worth one conversation with your CPA about what each state expects. That conversation is cheap. Discovering the answer during an audit is not.

Why the records matter more than the rules

Sales tax problems are rarely found in the month they happen. They are found in an audit covering several years, and by then a small monthly error has compounded into a number with interest on it.

The contractors who come through audits comfortably are not the ones who understood every rule. They are the ones whose books showed clearly what was paid, what was collected, and on which jobs — so questions had answers.

Related

• What contractors can actually deduct
• The chart of accounts a contractor actually needs
• Quarterly estimated taxes

General information about how contractor sales tax is commonly structured, not tax advice. Rules vary substantially by state and by the type of work — confirm your position with your CPA for every state you operate in.