Your P&L Says Profitable — Your Bank Account Disagrees

Sometime in late 2019, I sat across from a shop owner in a conference room in northern Virginia and showed him that his business had been losing money on every install job for three years. He had the P&L in front of him. He could see the net income figure. It said 22% margin.

It was wrong. Not fraudulent — the accounting was technically accurate. Operationally useless.

That moment is why I write about this. The P&L lying by telling the truth is not a rare event. It is the default condition for a small trade shop that hasn't built the right lens.

Net Income Is an Accounting Number, Not a Bank Number

Here is the foundational issue. Under accrual accounting, which is how most shops over a certain size file their taxes and run their books, revenue is recorded when it's earned, not when cash arrives. You complete a $4,200 split system install on a Thursday. You invoice the homeowner. That $4,200 appears on your income statement the moment you invoice it. If the homeowner takes 30 days to pay, the $4,200 is not in your bank account. But it's on your P&L.

Nothing went wrong. Nobody did anything wrong. The P&L and the bank account are measuring different things, and a profitable P&L combined with an empty checking account can coexist indefinitely without anyone making a mistake.

This is the same diagnostic as the install-loss problem I found in 2019. That owner didn't know he was losing money because his financial information was built at the wrong resolution. Wrong instrument, wrong reading.

Receivables Lag

Money earned but not yet collected. The measure is days sales outstanding: accounts receivable divided by trailing revenue for the period, times the number of days. For a residential HVAC shop doing mostly same-day service and homeowner installs, DSO should be 12 to 22 days. Most homeowners pay on completion or within a week.

When I see a residential shop running 35-plus days, there's almost always a small commercial maintenance contract portfolio buried in the mix, billing net-30, and the owner hasn't separated those receivables from the residential side to see what they're doing to the cash cycle.

Loan Principal Payments

When you make a monthly payment on a truck note, that payment has two components: interest and principal. The interest portion shows up on your income statement as an expense. The principal portion does not. It reduces your bank account and reduces your liability on the balance sheet, but it never touches net income.

I've written before that truck operating cost per billable hour is the most underpriced item in residential HVAC. The principal drain is part of why. Owners look at the income statement and think they've accounted for the trucks. They've accounted for the fuel. They've accounted for the interest. The principal is leaving the bank account every month, and the P&L has no record of it.

Owner Draws

When a working owner takes a draw against the business, that draw hits the balance sheet as a reduction in equity, not the income statement as an expense. The P&L doesn't see it.

The S-corp math I walk through with clients: the IRS requires reasonable W-2 wages for working owners, but the management accounting problem runs parallel to the tax question. Say you're pulling draws on top of your W-2. Your income statement shows only the W-2 as a labor cost. Your bank account is down the full amount. The gap is real and invisible on the P&L, and it will confuse you every time you try to reconcile the two stories.

The Receivables Problem Gets Worse on the Commercial Side

There's advice that circulates at every contractor association meeting and in most trade press articles on seasonality: add commercial service accounts to smooth out the residential slow season. It's bad advice for most shops under 12 trucks, and the reason is cash timing.

At Atlantic Comfort Partners, I watched shops that had grown commercial revenue to 15 or 20 percent of total simultaneously degrade their cash conversion cycle. The shops looked better on revenue. They looked worse on cash. The PE analysts noticed before the owners did because the analysts were running cash flow models and the owners were reading the P&L.

Commercial accounts pay net-30 or net-45, routinely. Some municipal and property-management accounts run net-60. Your residential customers mostly pay on completion or within a week. When you shift revenue mix toward commercial without adjusting your billing and collections process, you've extended the time between doing the work and getting paid while your payroll cycle hasn't moved.

I watched the same pattern after the SEER2 transition in shops that absorbed the equipment cost increases without passing them through. Revenue line improved. Equipment cost went up. Labor rate stayed flat. The cash the revenue actually produced shrank. The mechanism is different; the result is the same: the surface number looks fine while the underlying cash position erodes.

Slow-paying accounts you haven't modeled into your cash forecast will hurt you. Know your DSO by account type before you commit to a commercial contract.

What I Found in 2019

Back to that 14-truck residential HVAC shop in a mid-Atlantic suburb. Nine years in business. The owner ran a good install crew, low call-back rate, customers liked him.

When my team pulled his P&L for acquisition diligence, net income said 22% margin. I ran the management P&L with his labor charged at market rate, what he'd pay a working foreman with his diagnostic skills, and the real margin was closer to 6%. The same calculation I walk clients through now: your labor is a real cost of producing revenue, and if you're not charging it at market in your management books, your gross margin is fictitiously high.

That was the install-loss story. The cash story was a third number entirely. He was carrying 47 days of receivables on a small commercial maintenance contract portfolio he'd added two years earlier to smooth seasonality. Nobody had run the DSO. Nobody had modeled what net-30 billing on $180,000 in annual commercial contracts would do to the working capital cycle.

I have a scar on my left forearm from a reversing valve I burned myself on in 2012. I mention it occasionally when I'm on a Zoom with a contractor deciding whether to trust my read on their field operations. I mention it here for a different reason: I came up in those trucks. When I tell you the financial picture and the field picture are the same diagnostic, I mean it from both sides. That owner wasn't careless. He was running his business on instruments that weren't measuring what he thought they were.

The Fix Is a 13-Week Cash Flow Forecast

When a shop owner tells me they're going to solve a cash problem by selling more jobs, I understand the impulse. More revenue feels like more cash. It isn't, necessarily. In some cases more revenue accelerates the cash problem: more receivables lag, more payroll to cover, more equipment purchased before the customer pays.

The right instrument is a 13-week rolling cash flow forecast. Not a P&L projection. A cash forecast: what cash comes in, week by week, and what cash goes out, week by week, including principal payments, draws, tax deposits, and everything else your income statement ignores.

At Atlantic Comfort Partners, we required acquired shops to produce a 13-week cash flow within 90 days of close. Not because PE firms are sophisticated. Because it's the minimum information needed to run a business that has debt service. Independent shops have the same debt service. The fact that an acquirer demands this within 90 days of close and an independent owner has never built one is not a sophistication gap. It's an information gap.

The DSO calculation is the most direct entry point into the cash picture for most trade shops. A shop doing $1.2 million in annual revenue carries roughly $3,300 in receivables for every day of DSO. Cut DSO from 44 days to 28 days and you've freed up approximately $53,000 in working capital, without selling a single additional job, without hiring, without new equipment. By collecting what you're already owed, faster.

Here's what to do with that number.

Pull the gap. Open your bank account. Open your most recent month's P&L. Write down the current balance and the net income figure. Write down the difference. Now sort that difference into three buckets: receivables not yet collected, principal payments on debt, owner draws. You won't allocate it perfectly the first pass. Do it anyway.

Calculate your DSO. Your accounting software surfaces this in under five minutes. Accounts receivable divided by trailing 90-day revenue, times 90. If your AR balance is $62,000 and your trailing 90-day revenue is $300,000, your DSO is 18.6 days. If it's $115,000 on the same revenue, your DSO is 34.5 days. Track it monthly. The trend matters as much as the level.

Pull your debt service schedule. For every loan with a monthly payment, write down the total payment and the interest portion. The difference is principal. Add up all the principal payments. That's the monthly cash drain your income statement doesn't show.

Lay out 13 weeks. Columns are weeks, rows are cash in and cash out. Cash in means expected collections, not revenue booked. Cash out includes payroll, vendor payments, full debt service, draws, and tax deposits. The first version will be rough. Build it anyway.

The P&L will keep saying profitable. The bank account will keep telling a different story. You need both instruments calibrated before you can act on either.

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FAQ

My accountant says I'm profitable — why doesn't my bank account show it?

Your accountant is probably right, and so is your bank account. They're measuring different things. Accrual-basis accounting records revenue when it's earned, not when cash arrives, so a profitable P&L and a low bank balance can coexist without any error on anyone's part. The real question is whether you've looked at the three places cash goes that net income doesn't capture: receivables not yet collected, loan principal payments that reduce your bank balance but not your income statement, and owner draws that hit equity rather than expenses.

What is days sales outstanding and why does it matter for a small HVAC or plumbing shop?

DSO is the average number of days between when you invoice and when you collect. Calculate it as accounts receivable divided by trailing 90-day revenue, times 90. For a residential shop doing mostly same-day service, DSO should be 12 to 22 days. If it's higher, cash is sitting in uncollected receivables instead of your bank account. On $1.2 million in annual revenue, each additional day of DSO ties up roughly $3,300 in working capital. Knowing your DSO and tracking it monthly costs five minutes in your accounting software.

Is a 13-week cash flow forecast something a small shop can actually build?

It's a spreadsheet. Columns are weeks, rows are cash in and cash out. Cash in means actual expected collections, not revenue booked. Cash out includes payroll, vendor payments, full debt service, draws, and tax deposits. Private-equity operators require this from every acquired shop within 90 days of close because it's the minimum information needed to run a business with debt service. Independent shops have the same debt service. The first version takes a few hours. Build it anyway.

My draws are how I pay myself — are you saying that's wrong?

No. Draws are normal and often tax-efficient, particularly in an S-corp where your W-2 is set at a reasonable compensation level and additional distributions come out as draws. The issue is not the draw. It's that a draw reduces your bank account and your equity without appearing as an expense on the income statement. When you're trying to reconcile why the P&L looks healthy and the checking account doesn't, draws are one of the buckets to check. The management accounting discipline is to account for your own labor at market rate on your internal P&L, separate from whatever the tax return shows.

Should I avoid commercial accounts if they pay slower?

Not necessarily. But understand the cash-flow impact before you commit. A commercial maintenance contract billing net-30 on $150,000 in annual revenue ties up roughly $12,500 in receivables at any given time compared to the same revenue from residential customers paying on completion. That's a real working capital cost. If the margin on the commercial contract is higher and you've modeled the receivables timing into your cash forecast, it can work. The problem I watched repeatedly at Atlantic Comfort Partners was owners adding commercial revenue without adjusting their cash model, then being surprised when growth made the cash problem worse.

How do I know if my cash problem is a timing problem or a margin problem?

Run the 13-week cash flow and run a corrected management P&L side by side. A timing problem means cash is late arriving: DSO is high, collections lag, but the margin on completed work holds up when you run the numbers honestly. Fix it by tightening billing and collections. A profitability problem means the work itself isn't generating enough margin to cover overhead, debt service, and your own labor at market rates, and the corrected P&L shows it even when receivables are current. Most shops I work with have both problems at once, which is why fixing the timing problem first is useful. Once the receivables are moving, you can see the margin problem clearly without the distortion.