Construction Working Capital and the Cash Conversion Cycle
There is a hard truth in construction finance that catches even experienced contractors off guard: a company can be profitable on every job and still run out of money. Profit is an accounting outcome — revenue earned minus cost incurred. Cash is a timing outcome — money in the bank on a given day. In construction, those two things move on very different schedules, and the gap between them is where contractors fail.
The reason is structural. A contractor spends money — on labor, materials, equipment, and subcontractors — weeks or months before it collects the cash for that work. It performs the work, then bills for it, then waits for the owner to process and pay, then finally collects. Meanwhile the next job has already started spending. Profit is being earned the whole time, but cash is perpetually behind. Working capital is what bridges that gap, and managing it is not optional — it is the difference between a growing company and a bankrupt one.
This article walks through what working capital is, how the construction cash cycle works, why retainage and underbillings quietly trap cash, how to measure the cycle with the cash conversion cycle, why growth makes all of this worse, and the specific levers a contractor can pull to free cash up.
0% – 80%
Of construction company failures are attributed to cash flow problems rather than a lack of profitable work (CFMA / industry surety analysis)
Working capital is current assets minus current liabilities — the cash and near-cash a company has available to fund its day-to-day operations. Current assets are cash, accounts receivable, retainage receivable, costs and earnings in excess of billings, and inventory. Current liabilities are accounts payable, accrued expenses, billings in excess of costs, and the current portion of debt.
Positive working capital means the company can cover its near-term obligations from its near-term assets. Sureties watch it closely — working capital is one of the primary inputs to a bonding program, and a contractor's bonding capacity is often a direct multiple of its working capital. But the headline working capital number hides a critical nuance: not all current assets are equally liquid. Cash spends today. A receivable spends in 45 days. Retainage receivable might not spend for a year. A balance sheet can show healthy working capital while the company cannot make payroll on Friday, because the working capital is locked up in assets that have not turned into cash yet.
The construction cash cycle is the journey from spending money to getting it back. Every stage takes time, and the cumulative time is what determines how much working capital a job consumes.
The stages of cash flow on a construction project
- Mobilize — spend on bonds, insurance, mobilization, submittals, and early material orders before any progress billing is possible
- Perform — incur labor, equipment, material, and subcontractor cost as the work is built
- Bill — prepare and submit a progress billing, typically once a month, for work completed in the prior period
- Wait — the owner or their representative reviews, certifies, and processes the application for payment over a period of days to weeks
- Collect — the owner releases payment, net of any retainage withheld
- Pay — settle accounts payable to suppliers and subcontractors, often timed against the cash that just came in
The trap is in the sequencing. A contractor mobilizes and performs for weeks before the first billing even goes out. Then the billing covers only the prior month. Then the owner takes time to pay it. By the time cash for month one arrives, the contractor has already funded months two and three out of its own pocket. The faster a job grows, the deeper that hole gets — which is the paradox that catches growing contractors.
Retainage is the percentage — commonly 5% or 10% — that an owner withholds from every progress payment and does not release until the project is substantially or fully complete. It is intended to give the owner leverage to ensure the work is finished and punch-listed. From the contractor's cash perspective, it is a structural drag that builds over the entire life of the job.
On a job with 10% retainage, the contractor collects only 90 cents on every dollar of work it bills, month after month, with the retained 10% accumulating as a receivable that will not turn into cash until the end of the project — which on a long job can be a year or more away. That retained amount frequently exceeds the entire profit margin on the job. In effect, the contractor's profit is the last money it sees, and it sits as locked-up working capital for the duration. The drag compounds when the contractor passes retainage down to its own subcontractors at the same rate, but it still has to fund all the non-retained costs — its own labor, its own equipment — at full price.
Track retainage receivable as its own line and age it like any other receivable. It is real money you have earned, and on multi-year programs it can grow into one of the largest assets on the balance sheet. Retainage that is collectible but uncollected is a cash recovery opportunity hiding in plain sight.
Underbillings — costs and estimated earnings in excess of billings — represent work the contractor has performed and cost it has incurred, but for which it has not yet billed the owner. An underbilling is, in cash terms, a job financing the owner with the contractor's money. The contractor has spent the cash on labor and materials, but it has not even sent the invoice yet, let alone collected.
Underbillings come from billing slower than the work is being put in place — falling behind on schedule-of-values updates, failing to bill stored materials, slow processing of change orders so that change-order work is performed but not yet billable, or simply a monthly billing cycle that always lags performance. Some underbilling is unavoidable given the timing of construction billing. Persistent or growing underbillings are a warning sign: they mean cash is being consumed by work that has not been converted into a receivable. The fix is billing discipline — billing as much of the completed and stored work as the contract allows, as early as the contract allows, every single period.
0 – 90 days
Typical range for days sales outstanding on construction receivables, before accounting for retainage that can extend collection by months (CFMA benchmarking)
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Measuring It: The Cash Conversion Cycle
The cash conversion cycle puts a single number on how long a company's cash is tied up in operations. In its general form it is days sales outstanding, plus days inventory outstanding, minus days payable outstanding.
The three components, in construction terms
- Days sales outstanding (DSO) — how long it takes to collect a receivable after billing; in construction this should be measured both with and without retainage, because retainage stretches it dramatically
- Days inventory outstanding equivalent — for contractors this is better thought of as the time work sits in costs-in-excess-of-billings, capturing the lag between performing work and billing it
- Days payable outstanding (DPO) — how long the contractor takes to pay its own suppliers and subcontractors after receiving their invoices
The logic is straightforward: the longer it takes to collect (high DSO) and the longer work sits unbilled (high inventory-equivalent days), the more cash is trapped. The longer the contractor can responsibly take to pay (higher DPO), the less of its own cash it needs. A shorter cash conversion cycle means less working capital is required to run the same volume of work. A negative cycle — collecting before you have to pay — is rare in construction but is the gold standard, and it is part of why owner-funded mobilization and front-loaded schedules of values matter so much.
This is the most counterintuitive and most dangerous dynamic in construction finance. Winning more work — bigger jobs, more jobs, a larger backlog — increases the amount of cash the company must front before collections catch up. Every new job mobilizes and performs ahead of its billings. A contractor that doubles its volume roughly doubles the cash it must carry in the gap between spending and collecting.
This is why profitable contractors fail during boom times, not just busts. The work is good, the margins are real, the backlog is full — and the company cannot fund the cash gap that all that new work created. Growth is not free; it consumes working capital in direct proportion to volume. A contractor planning to grow has to plan the working capital and credit to fund that growth with the same rigor it plans the work itself.
Before taking on a large new project, run a job-level cash flow projection, not just a profit estimate. Map the months where cumulative spending exceeds cumulative collections, and confirm the company has the cash or credit to cover the deepest point. A profitable job the company cannot fund will still sink it.
Working capital management in construction comes down to a handful of levers. None is exotic; the discipline is in pulling them consistently.
The practical levers for managing construction working capital
- Billing velocity — bill every period for the maximum the contract allows, including stored materials and completed change-order work; nothing frees cash faster than billing what you have already earned
- Retainage reduction — negotiate lower retainage rates, retainage that steps down at 50% completion, or early release of retainage on completed and accepted portions of the work
- Terms management — extend supplier and subcontractor payment terms responsibly so days payable outstanding lengthens, while never paying so late that you lose discounts or damage key relationships
- Change-order processing — turn change-order work into billable work fast; unprocessed change orders are pure underbilling
- The line of credit — maintain a revolving credit facility sized to the cash gap, drawn to bridge the trough between spending and collecting and repaid as collections arrive
- Front-loaded schedules of values — within the bounds of the contract, structure the schedule of values so that early activities carry adequate value, improving cash position in the months when the gap is deepest
The line of credit deserves a specific note. It is the standard tool for bridging the structural cash gap, and a well-run contractor maintains one even when it does not currently need it — because credit is far easier to arrange before a cash crunch than during one. But a line of credit funds a timing gap; it does not fund losses. A contractor that is drawing on its line to cover unprofitable jobs is not managing working capital, it is delaying a failure.
Profit and cash are not the same thing, and in construction the gap between them is wide enough to sink a profitable company. Working capital is what bridges that gap, the cash conversion cycle measures how wide the gap is, and retainage and underbillings are the structural reasons it stays wide. Growth makes it wider still. The contractors that endure are the ones that bill fast, manage terms on both sides, fight for reasonable retainage, keep a line of credit ready, and project cash with the same seriousness they project profit. Watch the cash, not just the income statement — the income statement will tell you the work was good long after the cash problem has already arrived.
Written by
Marcus Reyes
Construction Industry Lead
Spent twelve years running AP at a $120M general contractor before joining Covinly. Lives in the world of AIA G702/G703, retainage schedules, and lien waiver deadlines. Writes about the construction-specific workflows that generic AP tools get wrong.
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