A contractor can be profitable on paper and short on cash in the same month, because deposits arrive before costs and retainage arrives long after them. The accounting that fixes this is not more reports — it is costing at the job level and knowing which jobs are actually paying you.
Job costing: the whole discipline in one page
A company P&L tells you the year was fine. A job cost report tells you which work to bid more of. Every dollar that leaves the business should land against a job or against overhead — no third category, no unallocated pile at the end of the month.
- Direct labor — wages plus the burden: payroll taxes, workers compensation, and benefits. Burden commonly adds 20% to 35% on top of the hourly rate, and bids that use the bare wage lose money invisibly.
- Materials — assigned to the job when purchased, not when the invoice is paid.
- Subcontractors — with a signed agreement, a W-9, and a current certificate of insurance on file before the first check.
- Equipment — either an hourly internal rate charged to jobs, or actual cost allocated, so the excavator pays for itself in the numbers as well as in the yard.
- Overhead — allocated on a consistent basis so that job margin means gross margin, and you know what the company needs to clear.
Compare that back to the estimate on every job, not just the ones that went badly. The jobs that quietly came in 8% over are the pattern worth finding.
Overbilling — invoicing ahead of work completed — feels like a good month and is really a loan from your customer. Underbilling is the opposite: real profit sitting unbilled while you fund it. A simple work-in-progress schedule comparing costs incurred to amounts billed on each open job turns both into information instead of surprises.
1099 versus W-2 is the expensive one
Trades run on crews, and crews get paid the fast way. But the label on the check does not decide the classification — the working relationship does. The federal common-law test looks at behavioral control, financial control, and the nature of the relationship: who sets the hours, who supplies the tools and materials, whether the worker can take a loss, whether they work for others, and whether the arrangement is ongoing.
Several states go further with an ABC test, under which a worker is presumed an employee unless the hiring business proves all three prongs, including that the work performed is outside its usual course of business. A framing crew working for a framing contractor almost never clears that prong. If you get it wrong, the bill is unpaid payroll taxes for every open year, penalties, interest, and often a workers compensation audit assessment on top.
- 1Collect a W-9 before the first payment, every time — no exceptions, including for the guy you have known for ten years.
- 2Require a certificate of insurance from every sub, and re-verify it annually; uninsured subs frequently land on your workers compensation audit as your payroll.
- 3Use a written subcontractor agreement that reflects how the work really operates, not a template that describes a relationship you do not have.
- 4File Form 1099-NEC for subs paid $600 or more, due by January 31 — the deadline that catches contractors every year.
- 5If you are unsure about a specific worker, get the classification reviewed before the year closes rather than after a notice arrives.
Misclassification is the only mistake in the trades that gets more expensive every quarter you do not fix it.
The sales tax rule that surprises trades
Contractors are treated differently from retailers in most states. The common pattern is that a contractor improving real property is the consumer of the materials — you pay sales tax when you buy them and do not charge tax to the customer on the improvement. Other states distinguish a lump-sum contract from a time-and-materials contract, taxing them in opposite directions, and repair or installation of tangible personal property often follows yet another rule.
Two practical consequences. First, your bid must include the tax you will pay on materials if your state works that way, or you have quietly bid the job at a loss. Second, do not buy materials with a resale certificate unless your state actually treats you as a reseller. The sales tax guide covers registration, sourcing, and how to fix periods you have already missed.
Deductions the trades leave behind
- Vehicles — track business mileage or actual costs; heavier work trucks above the weight threshold have their own, more generous depreciation treatment.
- The home office as an administrative base — when your home is the principal place you handle bidding and admin, trips from home to job sites become deductible business miles rather than commuting.
- Tools and small equipment — a de minimis safe harbor lets most businesses expense items under a per-item threshold instead of capitalizing them, which covers most of the truck.
- Licensing, continuing education, safety training, and certifications tied to the trade.
- Per diem for overnight travel to out-of-town jobs, which is simpler to substantiate than collecting every meal receipt.
- Retirement plan contributions, which are the largest deduction most profitable contractors are not using.
Cash, taxes, and the seasonal swing
Trade income is lumpy, and the tax system is not. Quarterly estimated payments still come due on schedule regardless of whether the big job funded — see the estimated tax payment guide for how to set the number and the safe harbor that keeps penalties away. A rolling 13-week cash forecast covering payroll, material buys, and expected collections is worth more to a contractor than any other report, and it is the core of what CFO advisory does for growing shops.
If job costing is currently a spreadsheet nobody updates, that is the place to start — bookkeeping set up with job tracking from the beginning, and payroll with the burden allocated correctly so bids reflect reality. Once profit is consistent, the LLC versus S-Corp comparison usually deserves a look. The broader compliance picture for local operations is in the local business accounting guide. This article is general information, not tax advice for your specific situation.