WIP REPORTING

OVERBILLING AND UNDERBILLING, EXPLAINED.

QUICK ANSWER

Overbilling means you've billed more than the percentage of work complete on a job, and underbilling means the opposite: more work is complete than has been billed. Both appear on the WIP schedule, underbilling as costs and estimated earnings in excess of billings, and overbilling as billings in excess of costs and estimated earnings. Both come with real risk if they're left uncorrected.

The two positions are mirror images of one job tracking problem. Somewhere between the field and the billing office, the pace of invoicing stopped matching the pace of production. When invoicing is ahead, the company spends money it collected for work nobody has performed yet. When invoicing is behind, the company funds finished work out of its own pocket while waiting on itself. Either way, the WIP schedule is the only report that puts the two side by side per job, which is why a monthly WIP review catches both while a monthly AR aging catches neither.

BY JOSH LUEBKERPublished 2026-08-06Updated 2026-10-19
THE DEFINITION

WHAT IT MEANS.

Overbilling is billing more than the percentage of work complete on a job, and underbilling is the reverse, where more work is complete than has been billed.

Overbilling and underbilling sound like opposite problems, and mechanically they are, but both come from the same underlying issue: billing and job progress have moved apart. Overbilling means cash came in ahead of the work that earned it, which feels fine until the job's real cost to complete comes in higher than expected and that advance cash is already spent. Underbilling means work stays unbilled, which cuts cash flow on a job that might otherwise be perfectly healthy. Neither one is a disaster by itself, but both need to be caught and understood rather than just reported.

Overbilling occurs when the amount billed on a job exceeds the percentage of work complete, measured by cost incurred against total estimated cost. On the balance sheet it reads as billings in excess of costs and estimated earnings, a liability representing cash you collected for work you haven't performed. A moderate and consistent level of overbilling isn't automatically a red flag, because some billing structures are built to front load a little. The concern is overbilling that's large, growing, or concentrated on jobs where the cost to complete is uncertain, since that combination means the cash cushion can disappear fast if costs go over.

Underbilling goes the other direction. Work performed exceeds what has been billed, and it reads on the balance sheet as costs and estimated earnings in excess of billings, an asset representing earned but uncollected revenue. Underbilling is usually less dangerous than heavy overbilling, but it still cuts cash flow, because the company is financing completed work with its own capital until billing catches up. Chronic underbilling across a job portfolio is one of the more common and more fixable causes of cash flow strain we find.

COMMON MISTAKES

WHERE IT GOES WRONG.

01

Reading overbilling as being ahead

The belief is that billing ahead of the work means the company is ahead financially. Overbilling means cash came in ahead of work performed, which is fine when the cost to complete estimate is accurate and risky when the job's real cost comes in higher than expected. If that advance cash has already been spent elsewhere, there's nothing left in the job to absorb the overrun.

02

Calling underbilling a timing issue

The belief is that underbilling is only timing and will sort itself out. It does sort itself out eventually, but in the meantime it's cutting cash flow on jobs that might otherwise be healthy. Chronic underbilling across a portfolio compounds into a real cash problem well before anybody calls it one.

03

Watching the AR total instead of the WIP schedule

The belief is that a healthy looking AR total means the WIP position is fine. A healthy looking AR total can conceal significant overbilling or underbilling at the individual job level. That job by job view is what the WIP schedule is built to reveal, and it's the one thing a single AR total can never tell you.

HOW SPM FIXES IT

GETTING BILLING BACK IN LINE.

Correcting an overbilled position

Correcting overbilling means either slowing the billing pace so job progress catches up, or confirming the cost to complete estimate is accurate so the overbilled position is deliberate and understood rather than accidental. Both of those are acceptable answers. What isn't acceptable is managing the job without knowing which one you're looking at.

Correcting an underbilled position

Correcting underbilling means billing more promptly and completely for work already performed, catching change orders that were completed but never invoiced, and tightening the billing cycle so finished work doesn't stay unbilled for an extra cycle. Most of the money in an underbilled position isn't disputed by anyone. It simply hasn't been invoiced yet.

WHAT YOU GET

THE OUTPUTS, NAMED.

WIP schedule reviewed monthly, with overbilling and underbilling calculated per job rather than only at the portfolio level
Cost to complete estimates updated whenever job conditions change, instead of staying at the original bid
Change orders billed promptly once performed, so an underbilled position doesn't build up unnoticed
Overbilling monitored for size and trend, not just presence, because moderate overbilling is often normal
Billing cycle tightened so completed work is invoiced on the next cycle rather than the one after
$10.7M+
Client AR Recovered Since 2023
48
Active Trade Specializations
60 DAYS
Average Onboarding Time
PRICING

FLAT MONTHLY FEE. NO SURPRISES.

Three tiers, priced by your trailing twelve month revenue. Which one you're in depends on how much of the work you want off your desk. No hourly billing. No payroll. The one-time onboarding fee is right here in the table.

Last 12 months revenueMonthly feeOne-time onboarding
Under $1M$1,900 to $3,300$1,000
$1M to $3.5M$2,600 to $5,300$1,500
$3.5M to $6.5M$3,800 to $8,300$3,000
$6.5M to $9.5M$5,100 to $11,800$4,500
$9.5M to $12.5M$6,100 to $14,900$6,000
$12.5M to $15.5M$7,400 to $17,650$7,500
$15.5M to $18.5M$9,400 to $22,400$9,000
$18.5M+Quoted individuallyQuoted individually

The onboarding fee covers migrating your books back to the start of your last taxable year and getting you fully operational in 60 days. It's billed once, with your first invoice. It's the same for all three tiers. Your first month is prorated, and your monthly engagement starts on the first of the first full month.

Range reflects the three tiers below. Which one you're in depends on how much of the work you want off your desk. No payroll. No hidden line items. The onboarding fee is right here in the table.

Core

You stop guessing.

You get the CFO work. Job costing built against the way you estimate, a 13 week cash forecast, monthly WIP, and a meeting every month that ends in decisions and never in a report.

Your bookkeeper still does the books.

Strategic

Every job shows its margin while it is still open.

Everything in Core, plus the bookkeeping and bank reconciliations done for you, and the job costing and WIP software set up, loaded with your cost codes, and managed every month. Use your own online software, or move to ours and we cover it.

A bookkeeper we choose does the books and reconciliations. No payroll.

Platinum

You approve, and the money side gets handled.

Everything in Strategic, plus a controller we choose who handles your bills and receivables for you the way an in-house controller would. They call vendors, pay the bills and keep the accounting current. We plan the cash flow first, and you approve every payment because it is your money.

A controller we choose does the payables and receivables. No payroll, no pay applications, no collections.

COMMON QUESTIONS

FREQUENTLY ASKED.

Sureties read the WIP schedule to judge whether your revenue recognition looks healthy. Significant overbilling can signal cash that's effectively borrowed against future performance, and heavy underbilling can signal collection or billing process problems. Both of those feed the underwriting decision, which is why an underwriter reads the schedule line by line instead of skimming the totals.

No. A moderate and consistent overbilled position is normal, because some billing structures are built to front load slightly. What we look at is size, direction, and where it is concentrated. Overbilling that's large, growing month over month, or concentrated on jobs with an uncertain cost to complete is the combination that turns into a cash problem when the overrun comes in.

Three tiers, and which one you are in depends on how much of the work you want off your desk. Core is where you stop guessing: job costing built against the way you estimate, a 13 week cash forecast, monthly WIP, and a monthly meeting that ends in decisions, while your bookkeeper keeps doing the books. Strategic is where every job shows its margin while it is still open: a bookkeeper we choose does the books and the bank reconciliations, and the job costing and WIP software is set up and managed for you, on your own online software or ours. Platinum is where you approve and the money side gets handled: a controller we choose handles your bills and receivables the way an in-house controller would, and you approve every payment. No payroll. No scope gaps.

Sixty days. We migrate your books back to the start of your last taxable year, set up ControlQore, and build your job costing structure from scratch. Fully operational in two months.
WHAT THIS TIES INTO
Josh Luebker, SPM The Construction CFO
Josh Luebker
FRACTIONAL CFO · SPM THE CONSTRUCTION CFO

Josh Luebker is a master electrician turned construction CFO, president of SPM The Construction CFO and author of CONTROL: C.F.O.S. Construction Financial Operating System.

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