Cash Flow for Contractors: Why a Profitable Year Can Still Leave You Short on Payroll

An electrical contractor I worked with came out of a record year. Revenue up 30%, more crews in the field than ever, a backlog that stretched into the following spring. On paper the company made money. Then in February the owner called me because he could not make payroll without dipping into his personal line of credit. The business was profitable and broke at the same time, and he could not understand how both could be true.

That gap is the whole problem with cash flow for contractors. Profit is what the job earns on paper once it closes out. Cash is what is actually in the account on the Friday you have to pay your people, your suppliers, and your fuel bill. Those two numbers live on different calendars, and in the trades they can be months apart. A busy contractor can be earning solid margins on every job and still run out of money, because the work gets done long before the money shows up.

This is not a rare edge case. It is the single most common way a growing trades business gets into trouble, and the more you grow, the worse it gets. Every new crew and every larger job pulls more cash out of the business before a dollar comes back in. Growth, done without a cash system, is exactly what kills profitable contractors.

Profit Is an Opinion. Cash Is a Fact.

Here is the sentence that should be on the wall of every trades shop: you do not go out of business because you are unprofitable. You go out of business because you run out of cash.

A U.S. Bank study of failed companies, conducted by former banker Jessie Hagen, found that 82% of business failures traced back to poor cash flow management or a poor understanding of cash flow, not to a lack of demand or a bad product. Construction feels that harder than almost any industry, because it is capital intensive and paid on a delay. Business survival data shows that close to four in ten construction firms do not make it past five years, and more than half are gone within ten. The jobs were not always the problem. The timing of the money was.

Profit is an opinion because it depends on estimates, on how you book revenue, on whether that change order ever gets approved. Cash is a fact. It is either in the account or it is not. When an owner tells me the business is doing great and the bank balance says otherwise, the bank balance is the one telling the truth. Learning to run the company on cash, not just on the profit and loss statement, is the shift that separates a shop that scales from one that stalls.

Where Your Cash Actually Goes to Hide

When a profitable contractor is short on cash, the money has not disappeared. It is sitting in four predictable places, and most owners have never named them out loud.

Retainage. On most contracts, the customer holds back 5% to 10% of every invoice until the job is substantially complete, which is often 12 to 18 months after you actually did the early work. That is your profit, frozen, funding someone else’s project. It is common for a contractor’s entire net margin to be locked up in retainage across active jobs. (There is movement here: California’s SB 61 caps retention on most private projects at 5% starting in 2026, which helps, but the structural drag remains.)

Slow payment. The average commercial construction invoice now takes about 83 days to turn into cash, up from 76 days in 2023 and 71 in 2020. Subcontractors wait longer, roughly 92 days, because they sit at the bottom of the pay-when-paid chain. Rabbet’s 2024 Construction Payments Report put the cost of slow payment to the US construction industry at about $280 billion in a single year, adding an estimated 14% to what the country spends on building. You are financing that delay out of your own pocket.

Mobilization. You fund the front end of every job before you can bill for it. Materials, permits, staging, the first weeks of labor. That is typically 10% to 20% of the contract value going out the door before the first invoice goes in. On a big job that number is enormous, and it is the reason winning a large contract can actually make your cash position worse before it makes it better.

Under-billing. This is the quiet one, and it is a billing discipline problem, not a market problem. If you have done $400,000 of work on a job but only billed $340,000, that $60,000 gap is you loaning the customer money for free. Contractors under-bill when invoicing lags the field, when change orders pile up unsigned, or when nobody owns the billing calendar. Over-billing, being paid ahead of the work, feels good but is borrowed cash you will have to earn back later. A healthy shop watches both and investigates any variance beyond about 2% of contract value.

The Billd 2025 National Subcontractor Market Report, which surveyed more than 800 subcontractors, general contractors, and suppliers, found that 43% of subcontractors do not have enough working capital to absorb an unexpected expense or a project delay, and 40% keep half to all of their profit tied up in the business just to fund day-to-day operations. That is not a group of failing companies. That is the normal state of profitable trades businesses that have never built a cash system.

The Numbers That Belong on Your Wall

In a Business Operating System, you run the company on a short list of numbers, reviewed every single week, with one person accountable for each. That is the Data component, and the tool is a weekly Scorecard. Most trades owners fill their Scorecard with revenue and job-completion metrics and never put a single cash number on it. That is a mistake. If cash is what kills profitable contractors, cash belongs on the board.

The handful of measurables I put in front of trades clients looks like this:

Cash on hand, and weeks of payroll it covers. Not just the balance, but the balance translated into “how many Fridays can I make payroll with zero new money coming in.” Aim to always know that number.
Accounts receivable aging. How much is owed to you, broken into current, 30, 60, and 90-plus days. The 90-plus bucket is where money goes to die.
Days to get paid (your own DSO). Track your real average against that 83-day industry benchmark and drive it down.
Retainage outstanding. The total your customers are holding. Watching it makes you chase releases instead of forgetting them.
Billed versus earned (the over/under-billing gap). Are you invoicing everything you have actually completed, every week?

You do not need enterprise software to start, but a tool that keeps the Scorecard live and assigns an owner to each number makes the discipline stick. This is exactly what a platform like Ninety.io is built for: a weekly Scorecard the whole leadership team looks at together, so a cash number sliding in the wrong direction becomes an issue you solve in Monday’s meeting instead of a surprise you discover in February. The tool is not the point. The weekly rhythm of looking at the right numbers is the point.

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What the Fix Looked Like for the Electrical Shop

Back to that electrical contractor who could not make February payroll. When we pulled the numbers apart, the profit was real. The cash problem was entirely structural, and it was fixable without winning a single new job.

Three things were bleeding him. First, billing lagged the field by two to three weeks because the office waited to invoice until a job phase felt “done,” so he was chronically under-billed by a low six-figure amount at any moment. Second, nobody owned retainage, so more than $200,000 in completed-work holdbacks was sitting uncollected, some of it more than a year old. Third, he had no forward view of cash at all; he looked at the bank balance the day the bills came due and hoped.

The fixes were unglamorous. We moved to progress billing on a fixed weekly calendar so invoices went out as work was earned, not after a phase closed. We made his office manager the named owner of retainage collection, with a standing task to chase every release at substantial completion. We built a rolling 13-week cash flow forecast, one page, updated every Monday, so he could see a shortfall six weeks out instead of six days out. And we put cash on hand, AR aging, and days-to-get-paid on the weekly Scorecard.

Within a quarter he was funding payroll out of operations, not his personal credit line. Revenue did not change. The cash timing did.

I learned to respect this kind of discipline long before I did fractional COO work in the trades. I spent more than twenty years in operations at a large telecom, where a plan that was right on paper but wrong on timing still blew up in the real world, and the only defense was watching the actual numbers every week rather than trusting the forecast. Trades work is different in almost every way except that one. The money you earned is not the money you have. Only the second number keeps the lights on.

Signs Your Cash Flow Is Running the Business

Read these honestly. If three or more land, cash timing is quietly steering your company, not you.

You are profitable on paper but regularly sweat making payroll or paying suppliers.
You do not know, right now, how many weeks of payroll your cash on hand would cover.
You have never added up how much your customers are holding in retainage.
Nobody in the company owns collections or chasing retainage releases; it happens when someone remembers.
You invoice in bursts when the office has time, not on a fixed billing calendar.
You find out about a cash crunch the week it hits, with no forward forecast.
Winning a big job makes you nervous about cash rather than confident, and you are not sure why.

Where to Start This Week

Build one page: a rolling 13-week cash flow forecast. List the cash you expect in by week (real collection dates, not invoice dates) and the cash you have to pay out by week. The first time you fill it in, you will see your tightest week coming from more than a month away, which is the difference between a decision and an emergency.

Then assign one person to own collections and retainage, and put cash on hand and AR aging on your weekly meeting agenda so they get looked at every seven days. That is the entire starting move. See your cash before it arrives, give the chase an owner, and review the numbers on a rhythm. Profit will take care of the story your accountant tells at year end. Cash is what keeps you in business long enough to get there.

If your best year on paper still left you short in the bank, the problem is a cash system, not a sales problem. Book a call and we will map where your cash is hiding across your active jobs and build the weekly view that ends the payroll scramble. Want to start setting up the Scorecard and tracking your cash numbers yourself? Take Ninety.io for a free run and put your cash measurables in one place your whole team can see.

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