WIP schedule construction reporting is the financial backbone of a contractor’s business, and the work-in-process schedule is often the most scrutinized document a surety, lender, or auditor will request. A WIP schedule construction analysis compares what a job has cost, what revenue has been earned, and what has actually been billed to the customer. Read correctly, it tells you whether a contractor is healthy, whether profit fade is creeping in, and whether cash is being managed responsibly across the project portfolio.
Quick answer: A WIP schedule shows each contract’s price, costs to date, estimated cost to complete, percentage complete, earned revenue, and billings. Overbillings (billings in excess of costs and estimated earnings) mean you have invoiced more than you have earned and represent a contract liability. Underbillings (costs and estimated earnings in excess of billings) mean you have earned more than you have invoiced and represent a contract asset. Sureties and lenders read these two lines to judge cash management, profitability, and the reliability of a contractor’s estimates.
What a WIP Schedule Actually Measures
The work-in-process schedule exists because, for most construction contracts, revenue is not the same thing as billings. Under FASB Accounting Standards Codification Topic 606, revenue is recognized as a performance obligation is satisfied, and most construction contracts are satisfied over time rather than at a single point. That means a contractor earns revenue by performing work, not by sending an invoice. The AICPA & CIMA has published detailed guidance on how ASC 606 affects the construction industry, including the over-time recognition that underpins every WIP schedule.
Invoicing follows a contract billing schedule or a monthly pay application. Earned revenue follows the value of work actually performed. Those two figures rarely match in any given month, and the gap between them is exactly what the WIP schedule isolates and reports.
The AICPA describes the schedule plainly. As its construction guidance notes, “An invaluable tool in calculating the progress and value of ongoing work is work-in-progress (WIP) schedules,” and “Revenue is generated through a calculation, the percentage of completion.” The schedule converts day-to-day field activity into figures that belong on a financial statement.
A standard WIP schedule includes, for each open contract: the total contract price, total estimated cost, costs incurred to date, estimated cost to complete, percentage complete, earned revenue to date, total billings to date, and the resulting over or under billing. Contractors who work in the construction industry typically update this schedule monthly so the numbers can be cross-checked against the general ledger and the financial statements.
The schedule also serves as a reconciliation tool. The sum of every contract’s earned revenue should tie to the revenue reported on the income statement, and the totals of overbillings and underbillings should match the contract liability and contract asset balances on the balance sheet. When those totals do not reconcile, it usually means a job was recorded inconsistently between the field and the books, and that discrepancy needs to be chased down before any statement is finalized.
How Percentage of Completion Drives the Numbers
The most common way to measure progress on a construction contract is the cost-to-cost method, an input method permitted under ASC 606. You divide costs incurred to date by total estimated costs to arrive at a percentage complete, then apply that percentage to the contract price to calculate earned revenue.
Consider a simple example. A contractor signs a $1,000,000 fixed-price contract with an estimated total cost of $800,000. By month-end the job has incurred $400,000 in costs. That is 50 percent of the estimated total cost, so the contract is 50 percent complete. Earned revenue is 50 percent of $1,000,000, or $500,000, and earned gross profit to date is $100,000.
Now layer in billings. Suppose the contractor has invoiced the owner $560,000 through that same date. Earned revenue is $500,000, but billings are $560,000. The contractor has billed $60,000 more than it has earned. That $60,000 is an overbilling.
If instead the contractor had invoiced only $450,000, earned revenue of $500,000 would exceed billings by $50,000. That $50,000 is an underbilling. The same cost and estimate inputs can produce either condition depending entirely on how aggressively the contractor invoices.
This is why the estimate to complete matters so much. If the total estimated cost is wrong, the percentage complete is wrong, earned revenue is wrong, and the over or under billing is wrong. A reliable WIP schedule depends on disciplined, regularly updated cost projections from the field.
One practical caution applies to the cost-to-cost method: certain costs can distort the percentage if they are included without thought. Materials purchased and stored but not yet installed, or large upfront mobilization costs, can push the calculated percentage complete ahead of the physical progress on the job. Many contractors exclude or adjust for these items so the percentage reflects work performed rather than cash spent, which keeps earned revenue from being overstated early in a contract.
Overbillings: Billings in Excess of Costs and Estimated Earnings
Overbillings, formally “billings in excess of costs and estimated earnings on uncompleted contracts,” appear on the balance sheet as a current liability. Under current GAAP terminology, this is reported as a contract liability. The label is the point: the contractor has been paid for work it still owes the customer.
Front-loading a billing schedule, billing for stored materials, or collecting mobilization payments all create overbillings early in a job. Within reason, this is healthy. Overbillings finance the work and keep the contractor from funding the owner’s project out of its own pocket.
The risk is interpretation. A contractor sitting on heavy overbillings may simply have favorable billing terms, or it may have already spent cash that belongs to future work. If overbillings are propping up the bank balance, the business can hit a cash squeeze as those jobs close out and the billings run dry. Sureties watch for contractors who are, in effect, borrowing from their own backlog.
The timing of overbillings across a portfolio matters as much as the total. A company with several new jobs that were front-loaded will naturally show a large overbilling balance, and that position will unwind as those projects mature. The concern arises when overbillings stay elevated quarter after quarter while the underlying work is winding down, because that pattern signals the cash advantage is being consumed faster than new work can replace it.
Underbillings: Costs in Excess of Billings
Underbillings, formally “costs and estimated earnings in excess of billings on uncompleted contracts,” appear as a current asset, reported under current GAAP as a contract asset. The contractor has performed work and earned revenue it has not yet invoiced.
Some underbilling is normal, especially near the start of a job or when unapproved change orders are in process. Persistent or large underbillings are a warning sign. They can indicate slow billing practices, disputed work, unpriced change orders, or, most seriously, cost overruns that have not yet been reflected in a revised estimate.
Underbillings also strain cash. The contractor has paid for labor and materials but has not collected for them, so working capital funds the gap. A surety reviewing a contractor with growing underbillings will ask whether the company can carry that cash burden across its entire backlog.
It helps to separate the causes, because the remedy differs for each. Underbillings driven by timing, such as a pay application that lands a few days after month-end, resolve on their own. Underbillings driven by unapproved change orders depend on negotiation and documentation, and the contractor should be able to support every dollar with field records. Underbillings driven by cost overruns are the most serious, because they often mean the estimate to complete has not caught up with reality, and a revised estimate may turn an apparent asset into a recognized loss.
For owners and finance teams who want an independent read on whether these figures are stated correctly, audit and assurance services test the underlying estimates, costs, and billings that drive every line of the WIP schedule.
How Sureties and Lenders Read the Schedule
A surety underwriting bonding capacity reads the WIP schedule before almost anything else. The total over and under billing position, compared to prior periods, signals how a contractor manages cash and whether its estimates hold up over time. A swing from underbilled to overbilled across the portfolio can be reassuring or alarming depending on the cause.
Profit fade is the other thing they hunt for. If a job’s estimated gross profit margin shrinks from one WIP schedule to the next, it suggests the original estimate was optimistic or that costs are running over. Repeated fade across multiple jobs undermines confidence in every estimate on the schedule, including the backlog the surety is being asked to bond.
Lenders use the same schedule to evaluate working capital and the quality of the balance sheet. Underbillings are an asset, but they are a softer asset than billed receivables, because they depend on the contractor’s estimate rather than an invoice the owner has acknowledged. A careful reader discounts underbillings that look like buried overruns.
Both audiences also read the schedule alongside the contractor’s backlog and historical accuracy. A company that consistently closes jobs at or above their original estimated margins earns the benefit of the doubt on its open contracts. A company with a record of fade gets the opposite treatment, and every favorable line on its current WIP schedule is read with skepticism.
Common Red Flags on a WIP Schedule
A handful of patterns draw immediate scrutiny. Large underbillings late in a job, when most work should already be invoiced, often signal disputes or cost problems. Jobs that are nearly complete by cost but show little remaining profit may be heading toward a loss.
Estimated costs that never change across reporting periods can indicate the field is not updating projections, which makes every derived figure suspect. And contracts where billings exceed the total contract price point to billing errors or to change orders that were invoiced but never added to the contract value in the schedule.
Two more patterns deserve attention. A job that jumps from a healthy margin to a thin or negative one in a single period suggests either a missed cost or a long-delayed estimate correction, and either way the cause should be documented. Contracts that show a percentage complete near or above 100 percent while still carrying significant estimated cost to complete are internally inconsistent, and they usually mean the contract value or the cost estimate was entered incorrectly.
Reading these signals well takes context. Two contractors with identical overbilling totals can be in very different positions depending on job mix, billing terms, and where each project sits in its lifecycle.
Frequently Asked Questions
What is the difference between overbillings and underbillings?
Overbillings occur when a contractor has invoiced more than it has earned based on percentage of completion, and they are reported as a contract liability. Underbillings occur when a contractor has earned more than it has invoiced, and they are reported as a contract asset. Both are calculated by comparing earned revenue to total billings on each contract.
How is percentage of completion calculated on a WIP schedule?
The most common approach is the cost-to-cost method: divide costs incurred to date by total estimated costs to get the percentage complete. That percentage is applied to the contract price to determine earned revenue to date. ASC 606 permits this input method for performance obligations satisfied over time.
Why do sureties and lenders care about the WIP schedule?
The schedule reveals cash management, estimate reliability, and profitability trends across a contractor’s entire backlog. Sureties use it to set bonding capacity, and lenders use it to assess working capital and the quality of the balance sheet. Patterns such as profit fade or growing underbillings directly affect those decisions.
Are overbillings always a problem?
No. Moderate overbillings are a normal and healthy result of favorable billing terms, and they help finance the work. They become a concern only when a contractor relies on them for cash that has effectively already been spent, leaving a shortfall as jobs close out and billing slows.
The Bottom Line
A WIP schedule turns cost, estimate, and billing data into a clear picture of contract performance, and the over and under billing lines are where that picture comes into focus. Overbillings are a liability that can mask a cash squeeze. Underbillings are an asset that can hide cost overruns. Reading both against earned revenue, and watching how they move over time, is how contractors, sureties, and lenders judge the financial health of a construction business.
