Construction-in-Progress (WIP) Accounting: How Contractors Should Track WIP

If you only run one report every month, it should be WIP. Not the P&L. Not the balance sheet. WIP is the report that tells you whether the money on your bank statement is actually yours, or whether it's a customer deposit you haven't finished earning.

1. What WIP actually is

WIP — Work-in-Progress — is a monthly reconciliation that asks one question, per job:

"For the work we've actually done on this job, are we billed ahead, billed behind, or right on track?"

Every active job has three numbers behind it: a contract value (what the customer agreed to pay), an estimated total cost (what you think the job will cost when it's done), and what you've actually spent and billed so far. WIP takes those numbers and reduces each job to a single answer — over-billed or under-billed, by how much.

That's it. The accounting language around it can get heavy, but the underlying question is straightforward: are we collecting ahead of the work, or financing the customer?

2. Why WIP matters to an owner

WIP is the only report that connects the three things owners actually care about:

• Cash position — over-billing is short-term cash; under-billing is cash you've already spent on the customer's behalf.
• True profitability — a P&L can look great while your WIP shows margin quietly evaporating across multiple jobs.
• Outside trust — bankers, bonding agents, and investors all read your business through your WIP. A clean WIP wins capacity. A sloppy WIP loses it.

Most contractors who go out of business were technically profitable on the P&L. They ran out of cash because they were heavily under-billed, or burned through over-billings on the wrong jobs. WIP is the report that would have shown both — months before it was too late.

3. The three formulas

WIP is built on three simple calculations. You don't need an accounting degree to read them — you just need to know what each one is asking.

If the last number is positive, you've billed ahead of the work — you're over-billed. If it's negative, you've done work you haven't invoiced for — you're under-billed.

That single number, repeated across every active job and totaled at the bottom, is your WIP position for the month.

4. A worked example

Take one job, mid-stream:

• Contract value: $1,400,000
• Estimated total cost: $1,000,000 (so estimated margin is 28.6%)
• Costs to date: $400,000
• Billings to date: $650,000

Run the formulas:

• % complete = 400,000 ÷ 1,000,000 = 40%
• Earned revenue = 40% × 1,400,000 = $560,000
• Over / (under) = 650,000 − 560,000 = +$90,000 over-billed

5. Over-billed — what it really means

Over-billing isn't bad — early in a job, slight over-billing is healthy and is how you fund mobilization, deposits to suppliers, and first payroll. The danger is in how owners read it.

A useful test, every month, on every job:

• How much am I over-billed on this job today?
• How much cost is left to come through?
• If both of those land as expected, will I still be ahead — or am I about to be under-water?

6. Under-billed — what it really means

Under-billing is the more dangerous of the two, because it's invisible. The work has been done. The cost has been paid (labor, subs, materials). But the invoice hasn't gone out, or hasn't been approved, or is sitting in someone's draft folder.

Under-billing usually comes from one of four places:

• Unapproved change orders — work is done, paperwork isn't.
• Slow PM-to-billing handoff — costs hit the books faster than the billing team can catch up.
• Schedule-of-values mismatch — the SOV doesn't reflect how the work actually runs, so billing always lags the field.
• Aggressive estimate-to-complete updates — every time you raise estimated total cost, percent complete drops and earned revenue drops with it, even if nothing changed in the field.

7. WIP and cash flow

The fastest way to understand WIP is to read it as a cash statement in disguise:

• Total over-billings = customer cash you're sitting on. It will leave the business over the next 1–6 months as work gets built.
• Total under-billings = your cash you're sitting on the customer's job site. It comes back only when you invoice and they pay.

Pair WIP with a 13-week cash forecast and you stop guessing. You can see, in advance, the weeks where over-billings are about to burn off and the weeks where under-billed work is about to collect. That's the gap most owners are flying blind through.

8. WIP, bankers, and sureties

Every commercial lender and bonding agent who works with contractors is reading WIP first and the P&L second. They want to see:

• A consistent WIP, signed and dated, produced on a regular monthly cadence.
• Stable estimated margins — not jobs that swing five points every month.
• Reasonable, defensible over-billings (not aggressive front-loading).
• Aging under-billings that are being actively collected, not ignored.
• A clean tie-out between the WIP, the job cost report, and the general ledger.

A contractor with $5M in revenue and a clean WIP usually gets more bonding capacity than a contractor with $8M in revenue and a messy one. The numbers matter less than the trust the WIP creates.

9. A monthly WIP process that actually runs

A WIP report is only as good as the close behind it. A workable monthly rhythm:

1. Cutoff. Close the month for costs and billings — no late-dated entries after this point.
2. Cost-to-complete review. PMs update estimated cost-to-complete on every active job. This is where profit fade is caught.
3. Job cost tie-out. Confirm job cost matches the general ledger. Differences here are usually mis-coded subs or PO commitments.
4. Run WIP. Calculate percent complete, earned revenue, and over/under billing per job.
5. Owner read. Total over-billings, total under-billings, jobs with margin movement >2 points, and any job over-billed beyond a defined threshold.
6. Action list. Whose invoice needs to go out this week. Which change order needs to be approved. Which job needs a margin conversation with the PM.

10. Where Vortex OS fits

Vortex OS is not an accounting system, and it is not a project management tool. It's the operating layer abovethem — the layer that takes job costs from your accounting system, contract values and schedule-of-values from your project tools, billings and AR from QuickBooks, and bank activity from your accounts, and reconciles them into one owner view.

For WIP specifically, that means:

• Contract value, costs to date, billings, and estimated cost-to-complete pulled from the systems you already run.
• Percent complete, earned revenue, and over/under billing calculated automatically per job.
• Profit-fade and over-billing thresholds flagged for the owner before they become a problem.
• WIP totals tied directly to cash forecast and backlog, so you can see the next 90 days, not just the last 30.

QuickBooks is not the problem. The missing layer above QuickBooks is the problem. Vortex OS is that layer.

Learn more about the executive layer at Vortex OS Financial Intelligence, or how Vorty AI reads your numbers for you at Vorty AI.

Related guides

• Construction Accounting: The Complete Guide for Contractors — pillar guide.
• Best QuickBooks Alternatives for Construction (and When You Actually Need One)
• Retention Accounting for Contractors — coming next.
• Construction Backlog: How to Measure and Use It — coming next.

FAQ

What is WIP in construction accounting?

Work-in-Progress: a monthly report that compares what you've billed each customer to what you've actually earned on their job. It tells you, per job, whether you're over-billed (sitting on a customer deposit) or under-billed (financing the customer with your own cash).

How do you calculate percent complete on a job?

The standard cost-to-cost method is: costs incurred to date ÷ estimated total cost at completion. If you've spent $400,000 of an estimated $1,000,000 total cost, you're 40% complete.

How is earned revenue calculated on a WIP?

Earned revenue = percent complete × total contract value. A 40% complete job on a $1.4M contract has earned $560,000 in revenue, regardless of what's been invoiced.

What's the difference between over-billing and under-billing?

Over-billed means billings to date are greater than earned revenue — you've collected ahead of the work. Under-billed means earned revenue is greater than billings to date — you've done the work but haven't invoiced it yet.

Why do bankers and bonding agents care so much about WIP?

WIP is how sureties and lenders judge whether a contractor is healthy, predictable, and worth backing. A clean WIP with stable margins increases bonding capacity. A messy or under-billed WIP usually reduces it.

How often should a contractor run WIP?

Monthly at a minimum, as part of the executive close. Growing contractors review WIP positions every two weeks because the cash impact moves faster than monthly reporting can catch.

Can QuickBooks produce a real WIP report?

Not on its own. QuickBooks holds the cost and billing data, but it doesn't natively reconcile contract value, estimated cost-to-complete, percent complete, and earned revenue per job. That reconciliation either happens in a spreadsheet or in an operating layer above QuickBooks.

What is profit fade?

When a job's projected margin quietly drops month over month — usually because estimated cost-to-complete keeps creeping up. WIP is where profit fade shows up first, often months before the job actually closes.