5 Construction Bookkeeper Red Flags That Cost Contractors Real Money

A contractor walked into our office last year with a profit and loss statement showing $380,000 in revenue. One line. Construction Income, $380,000. He runs residential remodels, commercial fit-outs, and a service van, and his books told him nothing about which one was actually making money. If your monthly report looks like his, the 5 construction bookkeeper red flags below will show you what's missing, what it costs you at the job level, and how to fix it. None of the fixes require buying new software.

The stakes: 3 businesses hiding inside 1 income line

That contractor doesn't run one business. He runs 3: residential remodels, commercial fit-outs, and a service van handling small repairs. 3 different businesses with different margins, customers, and problems. They share a truck and a bank account, and that is all they have in common.

When the books treat all 3 the same, nobody can say which one is profitable. Maybe commercial is carrying the company. Maybe service is bleeding it. He doesn't know, because nobody set the books up to show him.

This isn't just a small-company problem. Our founder ran a 150-person retail operation across 7 states doing $24 million a year, and the books still couldn't say which stores were carrying the others until after the wrong staffing call was made.

Wondering whether your own bookkeeper is doing this to you? The free Bookkeeper Scorecard is 10 yes-or-no questions and takes about 2 minutes.

Accurate vs useful: what bookkeeping for construction companies should do

Here is what most contractors never get told: there is a difference between bookkeeping that is accurate and bookkeeping that is useful.

Accurate means every dollar in and out is recorded and the totals at the bottom are right. The IRS is happy. Your accountant has what they need.

Useful means the same dollars are sorted in a way that helps you make decisions. A construction company doesn't sell one thing. You sell new builds, remodels, service calls: different customers, different pricing, different costs. If those sales all land in one income line, your books are accurate but useless for running the business.

The bookkeeping word for this breakdown is segmentation. Different software calls it divisions, departments, business units, or profit centers: a tag on every transaction that lets you slice your income statement by the segment that earned it.

One clarification: segmenting your profit and loss is not job costing. Job costing tracks individual projects in progress, so you catch a problem on a single job before it kills your margin (our free Job Cost Calculator covers that side). Segmentation is the big-picture monthly report: which parts of the business are working and which aren't.

The 5 signs your bookkeeper doesn't understand construction

If your bookkeeper is doing 2 or more of these, they don't understand construction.

Red flag 1: Your income is 1 line

Whatever you sell (residential, commercial, service, new construction, remodel), it all collapses into Construction Income or Sales. A construction-aware bookkeeper gives you a profit and loss with a row for each segment you actually sell. There are 2 ways to set it up: separate income accounts per segment, or 1 income line tagged by segment. We label our segments Division, which builds a Profit and Loss by Division report. Either way, you finally see which segment is growing, which is shrinking, and which is making you money.

Red flag 2: Costs are 1 bucket per category, with no segment behind them

The same contractor's books showed Materials $312,000, Labor $180,000, Subcontractors $95,000. Each one is a single number. You can't tell whether the materials bleed is on residential or commercial, and you can't see the gross margin of each segment because the costs aren't broken out. When every transaction carries a Division tag, costs roll up by segment automatically.

Red flag 3: Subcontractors are buried in Materials

Say you paid an electrical sub $8,000 and it got coded to Materials. Now your materials look bloated and your sub spend is hidden. At year end, nobody knows who needs a 1099 because the subs are scattered through a bigger account. A construction-aware bookkeeper keeps Materials, Labor, and Subcontractors as 3 separate lines, at minimum.

Red flag 4: No system for 1099s and Certificates of Insurance

December rolls around and the office scrambles to collect W-9s from every sub paid more than $2,000. That threshold went up in 2026 (it used to be $600; see the IRS 1099 instructions), but the workflow matters for every sub, not just the ones over the threshold. The bigger risk is subs working on your jobs without an active Certificate of Insurance. If something happens on the job, your insurance company can audit you and reclassify that uninsured sub as your employee. We've seen the premium adjustment from those audits land in the tens of thousands. The right workflow: W-9 on file before the first invoice gets paid, and a Certificate of Insurance on file with a tracked expiration date.

Red flag 5: Reports show up, but nobody explains them

Your profit and loss lands in your inbox on the 15th. You glance at the bottom number, file it, move on. A construction-aware bookkeeper sits down with you for 30 minutes once a month and walks through what changed, what's getting better, what's getting worse, and what to do about it. Reports without a conversation are just paperwork.

How to evaluate a construction bookkeeper: 3 steps and a 6th red flag

One reality check first: your bookkeeper can only sort what you give them. The setup works only if you supply clean inputs each month: which job belongs to which segment, W-9s and Certificates of Insurance from subs, and receipts coded to the right job. The payoff comes fast: next month's report shows margin by segment, and by the end of the quarter you have enough data to decide which segment to lean into and which to back off.

Then take these 3 steps. They cost nothing.

1. Pull up your last profit and loss and count the income lines. If you only see 1 or 2, your books are too lumped to tell you anything useful.
2. Spend 20 minutes writing out the actual segments of your business: residential remodel, commercial build-out, service, new construction, whatever the real cuts are. Most contractors we work with have between 2 and 5.
3. Send that list to your bookkeeper and ask 1 question: can you set up our profit and loss to break out by these segments going forward? If the answer is "what do you mean by segments" or "we don't usually do that for a company your size," that's your 6th red flag.

If you're on QuickBooks Online

In QuickBooks Online the segmentation feature is called Locations, and Advanced Settings lets you rename it to Division. You need QuickBooks Online Plus or higher; Essentials doesn't include it (see Intuit's plan comparison). Ask your bookkeeper to turn it on, set up a Division for each segment, tag every income and expense transaction, and run a Profit and Loss by Division report.

Where Best Decision Project Tools fits

The problem behind all 5 red flags is the same: the owner can't see the business in segments. Best Decision Project Tools (BDPT) was built around that problem. Its Business Units feature lets you pick the label that matches how you think (Divisions, Locations, Cost Centers; 11 options) and list your actual segments. Pick a Division on an estimate, and the tag flows through to the project, the invoice, the receipts captured against the job, and the bills from subs. The CFO Dashboard shows 6 color-coded gauges (Overall Margin, WIP Income vs Progress, WIP Costs vs Progress, Days Cash on Hand, Collection Rate, Backlog Months) and filters by Division, so you see each segment's numbers instead of 1 blended total.

A worked example: 3 divisions, 4 jobs, 1 useful report

Here is the sample company from the episode, TC Summit General Contracting, a Phoenix-area contractor running 3 divisions:

• Residential Remodel: the Whitfield Kitchen Remodel, a $55,000 estimate with $33,297 in estimated cost. Planned gross margin: $21,703, or 39.5%, inside the healthy 35% to 45% range for most trades. A second residential job, the Cardenas Bath Remodel ($28,500), already closed at a 36% gross margin.
• Commercial Build-Out: the Beacon Office Build-Out, a $185,000 contract about 50% complete, with a $30,000 deposit paid and a $55,000 progress invoice still outstanding.
• Service & Repair: the Riverside HOA account, a $12,500 quarterly recurring contract running on small service tickets.

On a 1-line P&L, all of that collapses into a single income number. Broken out by Division, the owner can see that residential is planning and closing healthy margins, commercial has $55,000 sitting in unpaid progress billing, and service is steady recurring work. 3 different stories, none of them visible until the books were segmented.

FAQ: hiring and grading a construction bookkeeper

How is construction bookkeeping different from regular bookkeeping?

Construction companies sell several different things at once, and each job runs across weeks or months. Construction bookkeeping sorts income and costs by segment and by job, keeps Materials, Labor, and Subcontractors separate, and runs a 1099 and Certificate of Insurance workflow for subs. A generic small-business setup with 1 income line can be perfectly accurate and still tell you nothing about where you make money.

What does a construction bookkeeper do?

A construction bookkeeper sets up your chart of accounts around the segments you actually sell, tags every income and expense transaction to a segment and a job, and keeps Materials, Labor, and Subcontractors as separate cost lines. They also keep W-9s and Certificates of Insurance current for every sub and walk you through your reports each month. The output is a profit and loss you can make decisions with, not just file.

What questions should I ask a bookkeeper before hiring them?

Ask whether they can break your profit and loss out by the segments of your business, how they keep subcontractor costs separate from materials, what their W-9 and Certificate of Insurance workflow looks like, and whether a monthly review conversation is included. If they ask what you mean by segments, or say they don't do that for a company your size, keep looking. Our free Bookkeeper Toolkit walks through the full checklist.

Do I need QuickBooks Online Plus for Locations or Class tracking?

Yes. Locations and Class tracking are included in QuickBooks Online Plus and Advanced, not in Simple Start or Essentials. You can also rename Location to Division in QBO's Advanced Settings so your reports read as a Profit and Loss by Division.

What is the 1099 threshold for subcontractors in 2026?

For payments made on or after January 1, 2026, the federal 1099-NEC reporting threshold is $2,000 per sub per year, up from the prior $600, and it will adjust for inflation starting in 2027. The filing trigger changed, but the discipline didn't: collect a W-9 from every sub before their first invoice is paid, regardless of size. Some states keep lower reporting thresholds.

Grade your bookkeeper in 2 minutes

The fastest way to act on this is the free Bookkeeper Scorecard: 10 yes-or-no questions, about 2 minutes, and you walk away knowing which gaps your bookkeeper has and the estimated yearly cost of each.

Prefer to watch? The full episode is on YouTube:

And if you'd rather talk to a bookkeeper who actually understands construction, reach out here. Find us at BestDecisionBookkeeping.com and BestDecisionBusiness.com.

About Best Decision Bookkeeping

Best Decision Bookkeeping provides construction-aware bookkeeping and fractional CFO services for contractors and trades, and produces the Behind the Books YouTube series for owners who came from doing the work and now run the business. Learn more at BestDecisionBookkeeping.com and BestDecisionBusiness.com.