Finance

What is operating cash flow in construction?

Operating cash flow is the cash a contractor's core business brings in or uses up over a period: money collected from customers minus money paid out for labor, subs, materials, and overhead.

An office manager and contractor review invoices with a calculator and laptop in a construction office.
Review invoices, committed costs, and cash timing together before making project decisions. AI-generated illustration.

Operating cash flow measures whether the work itself is producing cash. It leaves out borrowing, loan payments, owner draws, and buying or selling equipment, which show up in the financing and investing sections of the cash flow statement. A contractor can report a profit and still have negative operating cash flow, because in construction the gap between earning revenue and collecting it is wide.

Think of it as the answer to a simple question the owner asks every Friday: if we stopped borrowing and stopped buying equipment, would the jobs pay for themselves? A company with steady positive operating cash flow can grow, absorb a slow-paying GC, and carry retainage. A company with negative operating cash flow is funding its customers with a credit line, whether it meant to or not.

How to calculate it

Accountants usually start with net income and adjust it for non-cash items and changes in working capital. For a contractor the big working-capital lines are receivables, retainage receivable, payables, retainage payable, and the overbilling and underbilling balances from the WIP schedule.

  • Add back depreciation on trucks and equipment (an expense that used no cash this period).
  • Subtract an increase in receivables or retainage receivable (revenue booked but not collected).
  • Subtract an increase in underbillings (work done but not yet billed).
  • Add an increase in accounts payable (costs incurred but not yet paid).
  • Add an increase in overbillings (cash billed ahead of the work).

Worked example

Say a concrete contractor finishes the year with $410,000 of net income. It sounds healthy. Here is what happened to the cash:

Illustrative operating cash flow for one year
ItemEffect on cash
Net income+$410,000
Depreciation+$95,000
Increase in accounts receivable-$260,000
Increase in retainage receivable-$180,000
Increase in underbillings-$70,000
Increase in accounts payable+$60,000
Operating cash flow+$55,000

Almost all the profit is sitting in other people's bank accounts: a GC that pays in 60 days, two school jobs holding retainage, and unbilled work on a big slab. If the contractor also bought a $120,000 pump truck with cash, its bank balance fell during a profitable year. That is the classic busy-but-broke pattern.

The fix is rarely more sales. In this case, billing the slab work monthly instead of at milestones and pushing the two school jobs through closeout would free up more cash than a new contract would bring in for months.

Common mistakes

  1. Reading the P&L as a cash report. Profit is not cash until it is collected.
  2. Ignoring retainage. It is earned revenue that can sit for months. Track it in a retainage tracking template.
  3. Letting underbillings grow. Unbilled work is a free loan to the customer.
  4. Paying subs and suppliers faster than you get paid without meaning to.
  5. Funding growth with operating cash. Bigger jobs tie up more cash before the first payment arrives.

Related terms

Operating cash flow connects to the cash flow projection, accounts receivable, and retainage. For the forward-looking side, see how to forecast cash flow for a construction business and how to fix a construction company that is busy but broke.

Frequently asked questions

Why is operating cash flow lower than profit for most contractors?

Because revenue is earned before it is collected. Slow pay, retainage, and unbilled work all hold cash back even though the profit is real.

Is negative operating cash flow always bad?

Not always. A fast-growing contractor may run negative for a period as receivables build. But it has to be funded from somewhere, usually a credit line, so it needs a plan.

Do bonding companies look at operating cash flow?

Sureties review the full financial statements, including the cash flow statement and working capital. Consistently negative operating cash flow can raise questions.

How can a contractor improve operating cash flow?

Bill on time and completely, chase retainage at closeout, negotiate payment terms, keep underbillings low, and align payment terms with subs to your own collection timing.

Written and edited by

Maurice Francois writes and edits construction operations guides for Smart Business Automator. More from Maurice on the Scaling Legends podcast.

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