Mastering WIP reports for construction profitability

To build an accurate picture of a business’s financial health, accounting teams need to log revenue when the company earns it, not when the client actually transfers the cash. But this process of revenue recognition becomes messy fast when managing multiple construction projects. Timesheets sit on a super’s clipboard until Friday. Material invoices land weeks after the trucks roll. Change orders get signed in the field and never make it into the books. By the time numbers hit the work-in-progress (WIP) report, they’re already stale. 

These reports serve as a snapshot of every ongoing project’s costs and billings, providing essential visibility of whether each project is under or over budget. Mastering them requires a connected system where field data reaches the back office in plenty of time.

To understand how construction WIP reports transform raw field data into the financial intelligence needed to protect margins, read on. This guide lays out all the moving parts, explaining what a WIP report is, how to get the math right, and the common accounting traps that distort project financials.

What is a WIP report in construction?

Construction WIP reports track the financial health of the firm’s ongoing projects. They’re how finance teams reconcile billings, costs, and earned revenue across every active job. Unlike project status reports, which provide an overview of project progression, WIP reports specifically monitor costs, earned revenue, and billings against estimated budgets. 

For finance leaders, WIP reports are the primary system for keeping period-end financials audit-ready. This process is a core part of how project-based accounting works in the construction industry. By pulling fresh data from field reporting software, teams can see exactly how billings stack up against actual costs.

What should a WIP report include? 8 essential data points

To keep financial health in focus, WIP reports typically require eight specific data points. If inputs are inconsistent in even one of these categories, billing calculations can quickly become inaccurate. Those categories are:

1. Contract value: This is the total price agreed upon, plus any approved change orders. It acts as the financial ceiling for revenue recognition.
2. Estimated costs at completion: This is a projection of the total spend required to finish the job. If this figure becomes outdated as material or labor prices climb, the firm may see a profit drop when the job closes.
3. Costs incurred to date: These are the actuals from the ledger, including fully burdened labor, materials, equipment, and subcontractor costs. This category covers everything the project has consumed, whether the invoice is paid or still accrued. Contractors must capture these costs in real time to maintain audit-ready records.
4. Percentage of completion: Firms can work out how much of the project they’ve completed by measuring costs incurred divided by total estimated costs.
5. Earned revenue: This is the contract value multiplied by the percentage of completion. It’s the dollar value of the work the crew actually finished on the jobsite.
6. Billed to date: This represents the total amount formally invoiced. Keeping an eye on the gap between this number and earned revenue helps contractors spot any cash flow discrepancies.
7. Over/underbilling: This is the difference between amounts billed and revenue earned. Overbilling means invoicing ahead of the work performed, which sits as a liability on the balance sheet. Underbilling means the work is done but not yet invoiced. While this shows up as an asset, it actively strains cash flow because the labor and material costs behind that work have already been paid.
8. Projected profit or loss: This is the expected margin of profit or loss, calculated by subtracting estimated costs at completion from the total contract value. Tracking this every month catches profit fade in time to re-forecast, rebid open scope, or chase change orders before the job closes.

How to calculate WIP in construction: 5 steps

Accurate WIP reporting requires the field and back office to remain in sync. For finance leaders, this means setting up a construction job costing workflow where every labor hour and receipt immediately codes to the right project. Here’s what that process looks like step by step.

1. Identify costs incurred to date.

Gather all costs the project has incurred, including labor, materials, and equipment. Audit-ready records must show all fully burdened labor expenses. Ledgers that fail to reflect taxes and benefits already expended on the jobsite will overstate profit figures.

2. Find the percentage of completion.

With total actual costs locked in, finance teams can determine the project’s overall progress. The team calculates this figure by dividing total costs incurred to date by total estimated costs at completion. 

Note: Outdated estimates for material prices or labor requirements will skew this percentage and misrepresent actual progress. Contractors need to ensure data is always as current as possible.

3. Calculate earned revenue.

After establishing a completion percentage, multiply it by the total contract value. This highlights the company’s earnings for performed work and offers a more precise metric than invoices or cash receipts.

4. Calculate over- and underbilling.

This step measures earned revenue against the total amount the contractor has billed the client. A positive figure indicates overbilling, creating a liability for work still owed. A negative figure means the firm is underbilling: The work is done but not yet invoiced, so the labor and material costs behind it are draining cash before the finance team can request payment.

5. Forecast the final profit or loss.

Finally, the finance team subtracts total cost estimates from the total contract value. Comparing this forecast against the original budget catches variances while the project is still active. This identifies profit fade early enough to adjust resources before the project impacts quarterly financials.

The benefits of WIP reporting

Done consistently, WIP reporting delivers four practical benefits:

• Accurate revenue reporting: Supports the over-time revenue recognition ASC 606 calls for on long-term contracts, typically via the percentage-of-completion method
• Early detection of at-risk jobs: Flags projects where costs are outrunning progress, so operations leaders can address inefficiencies early
• Improved cash flow visibility: Identifies over- and underbilling positions to prevent the mistake of spending today’s deposits on tomorrow’s liabilities
• Compliance and bonding capacity: Maintains the audit-ready standards required by Generally Accepted Accounting Principles (GAAP) and Accounting Standards Codification (ASC) 606 while building the trust necessary to secure larger projects with bonding companies

Common mistakes in WIP accounting

Even with a solid framework, certain accounting habits can distort the accuracy of a construction WIP report schedule. These errors often lead to financial surprises at the end of a project. Here are some of the most common mistakes to watch out for.

Inaccurate percentage-of-completion estimates

Sometimes, superintendents eyeball percent complete from the truck on a Friday afternoon, or PMs roll last month’s cost-to-complete forward because no new invoices hit. When that happens, revenue figures skew. If the estimated cost to complete the project is too low, the reported profit will be artificially high until the final invoices arrive.

Inconsistent billing period alignment

When “costs incurred” and “billed to date” figures cover different time frames, the resulting WIP report will be fundamentally flawed. Aligning the cutoff dates for labor hours, material invoices, and client billings is a must for an accurate comparison.

Failing to update WIP schedules regularly

Treating WIP reports as a quarterly task instead of a monthly or biweekly discipline makes it easy for minor errors to compound. Frequent updates ensure management is working with the most current data available.

Mixing direct and indirect costs

Not all indirect costs function the same way. Indirect job costs like jobsite supervision, equipment depreciation, and field trailer rent should tie to specific projects via burden rates. But that’s not the case for general overhead like office rent, executive salaries, and marketing. The mistake is dumping general corporate overhead into a job’s cost pool, which hides true profit margins.

Ignoring overbilling and underbilling signals

Treating a large overbilling position purely as extra cash is a risky oversight. These figures signal future obligations, so failing to account for them as liabilities can lead to a severe cash crunch during the final phases of a project.

Why WIP schedules fail (and how to fix them with Miter)

Inaccurate WIP schedules are usually the result of poor data quality, not bad math. When labor costs land in an enterprise resource planning (ERP) platform late, miss secondary burdens, or carry the wrong job codes, the data feeding the WIP schedule is broken before the report runs.

Miter addresses this data gap at the source. The platform tracks time in the field against specific cost codes. And because payroll runs directly within Miter, fully burdened labor costs like taxes, benefits, and workers’ comp post to a general ledger (GL) entry that syncs to the ERP. When job costing data lands in the accounting system accurately and on time, the WIP schedule more reliably reflects the actual financial position of every project.

Get in touch to see how Miter streamlines job costing and accounting integrations with platforms like Sage 300, Sage Intacct, Acumatica, Oracle NetSuite, and QuickBooks.

Frequently asked questions

How do construction firms automate WIP reporting?

Automation requires field-level data to flow directly into the ERP platform without rekeying. That means syncing field data with the firm’s accounting software so that cost-coded timesheets, material invoices, and subcontractor pay applications route to the right job codes automatically. When these data streams move without manual entry, the lag that usually hides profit fade disappears.

How often should firms update WIP reports?

Most firms stick to a monthly update to match their financial close. That said, on compressed-schedule jobs, projects burning heavy overtime, or thin-margin work where a few weeks of labor swings can erase profit, biweekly updates give the operations team a more current view.

What’s the difference between overbilling and underbilling?

Overbilling occurs when a firm invoices for more than the earned revenue, creating a liability on the balance sheet. Underbilling represents the opposite: The team has completed the work but hasn’t yet sent the invoice. While this appears as an asset, it frequently squeezes cash flow.