A WIP schedule for construction contractors is a financial report that lists every active contract in one place and shows, for each job, how much you’ve spent, how much you’ve billed, and how much revenue you’ve actually earned based on the work completed. It sits inside accrual accounting, matching revenue and expenses to the period the work happens rather than the period cash moves. Bonding agents, lenders, and CPAs all read it to judge the financial health of your company, and mistakes in it can shrink your bonding capacity, trip loan covenants, or create tax problems you didn’t see coming.
The Four Inputs Behind Every Project Row
Each row on the schedule represents one contract, and each row is built from four numbers. Get any of them wrong and every calculation downstream is wrong too.
- Total contract price. The full amount the client agreed to pay, including any signed change orders that adjusted the original scope. A change order is a formal document that legally changes the contract value, and it should hit this column as soon as it’s executed.
- Total estimated costs. Every anticipated expense needed to finish the job: materials, labor, equipment rentals, subcontractor fees. This is your baseline for how much work is left.
- Costs incurred to date. Money already spent from the start of the project through the current reporting period, including vendor payments, equipment charges, and internal labor run through payroll.
- Total billings to date. All invoices you’ve issued to the client, whether or not payment has come in. This is the accounts receivable side of the picture and feeds the over/underbilling calculation.
Costs incurred against total estimated costs drives the percentage-of-completion figure. Earned revenue against total billings tells you whether the project is overbilled or underbilled. Every other column on the schedule is calculated from these four.
Percentage of Completion and Earned Revenue
The percentage-of-completion method ties revenue recognition to the work you’ve actually performed rather than to the invoices you’ve sent. Under ASC 606, the accounting standard governing revenue from customer contracts, each contract lands on the balance sheet as either an asset or a liability depending on how your performance compares to what the client has paid.
The math is simple. Divide costs incurred to date by total estimated costs to get the completion percentage, then multiply that percentage by the total contract price to get earned revenue.
A Worked Example
Say you hold a $1,000,000 contract with $800,000 in estimated costs. You’ve spent $400,000 and billed the client $450,000. The WIP math:
- Percentage complete: $400,000 ÷ $800,000 = 50%
- Earned revenue: 50% × $1,000,000 = $500,000
- Estimated gross profit at completion: $1,000,000 − $800,000 = $200,000 (20% margin)
- Billing position: $500,000 earned − $450,000 billed = $50,000 underbilled
That $50,000 underbilling means you’ve done more work than you’ve invoiced for. Flip the numbers and bill $550,000 instead, and you’re $50,000 overbilled: you’ve collected more than your progress justifies. Both are normal in construction. The trouble starts when either position gets too large or lingers too long.
What Overbillings and Underbillings Actually Mean
Underbillings show up as a current asset on the balance sheet because they represent revenue earned but not yet invoiced. It usually happens when billing cycles lag the work or when costs stack up before a milestone triggers an invoice. Persistent underbilling is a cash flow warning: you’re spending faster than you’re collecting, and you can end up scrambling to fund the work in front of you.
Overbillings appear as a current liability because you’ve invoiced for work you haven’t yet performed. Most experienced contractors want to sit slightly overbilled across their portfolio because it keeps cash coming in ahead of expenses. Push it too far and the risk flips: as the project nears completion, remaining billing capacity shrinks, and you can struggle to cover late-stage costs when there’s little left to invoice.
These positions also move your working capital numbers. Underbillings inflate current assets, which can make the balance sheet look stronger than it is if collection is slow. Overbillings raise current liabilities and can weaken the current ratio. Surety underwriters check that large overbillings are matched by cash and receivables on the asset side. If the overbilled dollars have already been spent funding a different job, that’s a serious red flag.
Unapproved Change Orders
Unapproved change orders are one of the harder judgment calls on a WIP schedule. If you’ve incurred costs on work covered by a pending change order, those costs land in the WIP but the matching revenue doesn’t, at least not automatically. What you see is usually an underbilling reflecting real spending with no confirmed revenue behind it.
The treatment depends on whether recovery is probable. If approval and collection are likely, you can reflect the anticipated revenue, though profit recognition is generally deferred until the outcome is resolved. If recovery isn’t probable, the costs hit the project with no offsetting revenue, and projected gross profit drops. ASC 606’s rules on contract modifications and variable consideration govern the analysis, and getting it wrong can materially misstate your financial position.
Profit Fade: The Trend That Matters Most
Profit fade is what happens when a project’s expected gross profit at completion drops below what you originally bid. It’s the single most important trend to watch on a WIP schedule and the one that gets contractors in the most trouble with their surety.
Take the example above. Your original estimate was a 20% margin, or $200,000 of profit on $800,000 in costs. Three months in, the project manager revises total estimated costs to $850,000. Now $1,000,000 minus $850,000 leaves $150,000 of profit, a 15% margin. That $50,000 drop is profit fade. If the same pattern repeats across multiple jobs, you have a systemic estimating or execution problem.
A gain/fade analysis compares the original gross profit from your bid to the current expected gross profit at completion. Do it monthly at a minimum. Sureties and lenders run their own gain/fade analysis on your year-end financials, and a contractor who consistently fades will see tighter bonding limits and less favorable lending terms.
The common causes are labor cost overruns on labor-heavy contracts, material price increases that weren’t locked in, and scope creep from unapproved change orders that absorb costs without adding revenue. When fade shows up, the question isn’t only what went wrong on the job but whether the original estimate was realistic. If the bid margin was well above what you’ve historically hit on similar work, the estimate was probably aggressive from the start.
Building the Schedule
Compiling an accurate WIP schedule means pulling records from several places. The report can’t be more accurate than the inputs.
- Signed contracts and executed change orders. These are the legal basis for every revenue figure. Cross-check them against the latest budget projections to confirm estimated costs still make sense.
- Accounts payable ledgers and subcontractor invoices. The detailed trail of project expenses. Every charge needs to be coded to the correct project number.
- Payroll records. Wages, payroll taxes, and fringes have to be allocated to specific jobs. Misallocated labor is one of the most common sources of WIP error.
- Billing records. Every invoice issued to each client, whether or not it’s been paid.
Standardized job-cost codes in your accounting system keep expenses in the right WIP columns. Organizing by project number stops costs from being attributed to the wrong contract, an error that can make one job look profitable while another appears to be losing money.
The physical schedule sits in a spreadsheet or in integrated construction accounting software. Columns run across the top: project name or number, total contract price, estimated total costs, costs incurred to date, percentage complete, earned revenue, total billings, and the over/underbilling position. Each row is one active contract. Import contract values and current cost estimates from your signed agreements and latest budget revisions, pull actual costs from the general ledger, and pull billing totals from accounts receivable. Percentage complete and earned revenue are calculated fields. The last column subtracts billings from earned revenue.
The bottom row aggregates every project into a total contract value, total estimated costs, total earned revenue, and net over/underbilling. That aggregate is what external readers focus on first. A company net overbilled across all jobs is generally in a healthier cash position than one net underbilled, but the underlying details matter more than the totals.
Updating Cost-to-Complete
The estimated-costs column is the most volatile number on the schedule and the one that needs the most attention at every review. Early in a project, subtracting costs incurred from the original budget works fine. Once you’re past roughly 20-25% complete, factor in actual performance. If labor is running 10% over budget at the halfway mark, assuming you’ll hit the original number on the rest of the work is wishful thinking.
Project managers and accountants should sit down together on cost-to-complete monthly. The PM brings field knowledge of what’s actually happening on site; the accountant brings the numbers. Neither view alone produces a reliable estimate. This is where most WIP schedules go wrong: the review either doesn’t happen, or last month’s numbers get rubber-stamped.
Review Cadence and Who Sees It
Most construction firms update WIP monthly, with a harder look at each fiscal quarter-end and year-end. The year-end version feeds the financial statements your CPA prepares and drives correct tax and earnings reporting. Bonding agents use the schedule to calculate your backlog (total contract values minus revenue earned to date), which directly shapes the size of jobs you’re allowed to bid. Lenders use it to monitor loan covenants and debt-to-equity ratios. A well-documented WIP demonstrates professional management and often translates into better terms from both sureties and banks.
How the WIP Ties Into Your Federal Tax Return
Federal tax law imposes specific accounting rules on long-term construction contracts. Under Internal Revenue Code Section 460, taxable income from any long-term contract must generally be determined using the percentage-of-completion method, and the completion percentage is calculated by comparing costs allocated to the contract and incurred before the close of the tax year with estimated total contract costs. That mirrors the WIP calculation you already do.
When a long-term contract wraps up, Section 460 requires a “look-back” calculation. Because your annual returns during the contract were based on estimated costs that inevitably differed from the actual finals, the IRS trues things up. You recompute the tax you would have owed each year using actual contract price and costs and then pay interest on any underpayment or receive interest on any overpayment. The calculation is reported on IRS Form 8697, filed for any tax year in which you complete a qualifying long-term contract. The look-back doesn’t apply to contracts with a gross price at completion of $1,000,000 or less (or 1% of your average annual gross receipts for the three preceding tax years, if that’s lower), as long as the contract was completed within two years of its start.
Not every construction company is locked into percentage-of-completion for tax purposes. Section 460(e) exempts two categories: residential construction contracts, and other construction contracts entered into by a taxpayer who expects to complete the contract within two years and meets the gross receipts test under Section 448(c). For tax years beginning in 2025, that threshold is $31 million in average annual gross receipts over the prior three tax years, and it adjusts annually for inflation, so check the current IRS Revenue Procedure for the most recent figure.
Contractors who qualify can use alternatives like the completed-contract method, which defers all revenue and expense recognition until the project is finished. That method can be a real tax-planning tool because it delays taxable income, but it means your GAAP WIP schedule (still using percentage-of-completion) won’t match your tax return. Your CPA has to track both.
Mistakes That Undermine the Schedule
The most damaging WIP errors aren’t arithmetic. They’re judgment calls that nobody revisits.
- Stale cost estimates. Carrying forward the original budget month after month without adjusting for actual conditions. If material prices jumped or a sub’s scope grew, the estimated-costs column should reflect that right away.
- Misallocated costs. Charging expenses to the wrong project, inflating one job’s costs while understating another’s. Shared equipment and overhead labor are the usual culprits.
- Booking unapproved change orders as revenue. Anticipated revenue from unsigned change orders doesn’t belong in the contract price column unless recovery is probable under ASC 606.
- Job borrowing. Using overbilled cash from one project to fund shortfalls on another. The WIP may look balanced while the cash is already gone. Sureties watch closely for this pattern.
- Infrequent reviews. Updating quarterly instead of monthly. A lot can go wrong in 90 days, and by the time the fade shows up, the damage is done.
Surety underwriters have seen every version of these problems. Margin fades across multiple projects are the largest single red flag in their review. A one-time fade on an unusual job is understandable. A pattern of fading margins says the contractor is either bidding too aggressively or managing costs poorly, and neither builds confidence for the next bonding request.