Your general contractor just closed out Q3 with $4.8 million in billings. The bank account looks healthy. The project managers are saying every job is on track. Then your bonding company reviews the financials, and the underwriter flags $620,000 in overbillings that your books never recognized. Your bonding capacity gets cut by 30%, and you lose the bid on a $3.2 million school renovation because you can’t get bonded for it.
This is what happens when construction companies treat WIP accounting as optional. It’s not optional — it’s the single most important financial discipline that separates contractors who grow from contractors who plateau at the same revenue for a decade. WIP accounting for contractors tells you the truth about your jobs: whether you’ve billed more than you’ve earned (a liability you owe back in future performance) or earned more than you’ve billed (an asset that’s trapped in unbilled work). Without it, your income statement is fiction.
This guide covers everything a general contractor, subcontractor, or specialty trade contractor between $1M and $10M in revenue needs to know about WIP accounting — from the underlying methods to a full worked example with real numbers, and how WIP directly impacts your bonding capacity and tax liability.
Work-in-progress (WIP) accounting is a method of tracking revenue and costs on long-term contracts where the work spans multiple accounting periods. In construction, that’s most projects — a $1.2 million commercial buildout doesn’t start and finish in the same month, so you need a system to recognize revenue proportionally as you complete the work.
Here’s why this matters: standard cash-basis or accrual-basis accounting — the kind that works fine for a law firm or an e-commerce company — breaks down completely on multi-month construction contracts.
Cash basis recognizes revenue when you receive payment. But if you bill $400,000 in March and the GC pays in May, your March P&L shows zero revenue despite having a crew on-site burning through labor and materials. Your financials are useless for decision-making.
Standard accrual recognizes revenue when you bill. Better — but still wrong. If you front-loaded the billing schedule (which every smart contractor does to improve cash flow), your books show $400,000 in revenue when you’ve only completed $280,000 worth of work. You look more profitable than you are, and you can’t see the $120,000 liability hiding in your overbilling.
WIP accounting fixes both problems by tying revenue recognition to actual completion — measured by costs incurred, units installed, or milestones achieved. It’s the only method that gives you an accurate picture of job profitability at any point during the project.
Why your bonding company cares: Surety underwriters don’t trust your billing schedule — they trust your WIP schedule. It’s the first document they ask for, and it tells them whether your company is actually profitable or just generating cash flow through aggressive billing. A clean WIP schedule is the difference between getting bonded at $5 million and getting bonded at $2 million.
The two primary revenue recognition methods for WIP accounting contractors use are percentage-of-completion (POC) and completed contract. Your choice affects your income statement, your tax liability, and what your bonding company sees.
POC recognizes revenue proportionally as work progresses. The most common measurement is the cost-to-cost method: divide costs incurred to date by total estimated costs to calculate your completion percentage, then apply that percentage to the total contract value.
Formula:
Percent Complete = Costs Incurred to Date / Total Estimated Costs
Earned Revenue = Percent Complete x Total Contract Value
When to use it: POC is required under GAAP for most construction contracts and under IRS Rev. Proc. 91-64 for any long-term contract where the taxpayer has average annual gross receipts exceeding $29 million (adjusted for inflation). It’s also what bonding companies and banks expect to see.
Advantage: Gives you the most accurate picture of job profitability at any point during the contract. You can spot margin fade early — before the job is 100% complete and the damage is done.
CCM defers all revenue and cost recognition until the project is substantially complete. Your books show zero revenue and zero cost on a job until it’s done, at which point the entire contract hits the P&L at once.
When to use it: The IRS allows CCM only for contracts that will be completed within two years and for contractors with average annual gross receipts of $29 million or less (per IRC Section 460(e)). Even if you qualify, most bonding companies discourage CCM because it obscures job-level profitability during the contract period.
Advantage: Simplifies accounting and can defer tax liability. If you complete a job in January, you don’t recognize the income until your fiscal year includes that completion date.
| Factor | Percentage-of-Completion | Completed Contract |
|---|---|---|
| Revenue recognition | Proportional as work progresses | All at completion |
| Accuracy during project | High — shows real-time profitability | None — P&L is blank until done |
| GAAP compliance | Required for most contracts | Allowed only for small contracts |
| IRS requirement | Mandatory above $29M gross receipts | Allowed below $29M, <2 year contracts |
| Bonding company preference | Strongly preferred | Discouraged |
| Tax timing | Pay tax as you earn | Defer tax until completion |
| Complexity | Higher — requires monthly WIP updates | Lower — recognize at completion |
Practical reality: If you’re a contractor between $1M and $10M in revenue and you want to grow your bonding capacity, use percentage-of-completion. CCM might save you some accounting effort, but it cripples your ability to manage jobs in progress and it makes your surety underwriter nervous. POC is the professional standard for a reason.
This is where most contractors’ eyes glaze over — and exactly where the money hides. Every active project on your books has a billing position: either you’ve billed more than you’ve earned (overbilled) or you’ve earned more than you’ve billed (underbilled). Understanding this distinction is the entire point of WIP accounting for contractors.
Overbilling means you’ve invoiced the client for more than the revenue you’ve actually earned based on your completion percentage. The excess billing is a liability on your balance sheet — you owe that value back in future performance.
Example: You’re 40% complete on a $500,000 job but you’ve billed $250,000 (50% of contract). Your earned revenue is $200,000 (40% x $500,000). You’re overbilled by $50,000. That $50,000 is not profit — it’s an obligation to deliver $50,000 more in work than you’ve been paid for.
Why overbilling happens:
Why it matters: Overbilling is healthy in moderation — it means you have cash in hand before you’ve spent it. But excessive overbilling signals to bonding companies that you’re borrowing from future projects to fund current operations. If your overbillings consistently exceed 10-15% of your backlog, expect your surety to ask questions.
Underbilling means you’ve completed more work than you’ve invoiced for. The unbilled amount is an asset on your balance sheet — the client owes you for work already performed.
Example: You’re 60% complete on a $500,000 job but you’ve only billed $200,000 (40% of contract). Your earned revenue is $300,000 (60% x $500,000). You’re underbilled by $100,000. That’s $100,000 of work you’ve done that you haven’t collected for yet.
Why underbilling happens:
Why it matters: Underbilling is a cash flow killer. You’ve paid for labor, materials, and equipment out of pocket, but you haven’t collected for it. Chronic underbilling is the #1 reason profitable construction companies run out of cash. According to the Associated General Contractors of America (AGC), cash flow problems — not lack of work — are the primary cause of contractor failure.
| Overbilled | Underbilled | |
|---|---|---|
| Definition | Billed more than earned | Earned more than billed |
| Balance sheet | Current liability | Current asset |
| Cash flow effect | Positive — cash in hand | Negative — cash out the door |
| Healthy range | 5-15% of active contract value | Minimize — ideally near zero |
| Risk signal | Excessive = borrowing from future work | Chronic = cash flow crisis |
| Bonding impact | Moderate overbilling OK; excessive raises flags | Underbilling erodes working capital |
The WIP schedule is the master document that pulls everything together. Every contractor running POC accounting should produce a WIP schedule monthly — it’s how you track billing position, earned revenue, and estimated profit on every active project.
Let’s build one from scratch using a real scenario.
Project: Interior buildout of a 12,000 SF medical office
Contract value: $1,200,000
Estimated total cost: $960,000
Estimated gross profit: $240,000 (20% margin)
Billing to date: $780,000
Costs incurred to date: $576,000
Step 1: Calculate percent complete
Percent Complete = $576,000 / $960,000 = 60%
Step 2: Calculate earned revenue
Earned Revenue = 60% x $1,200,000 = $720,000
Step 3: Calculate earned gross profit
Earned Gross Profit = Earned Revenue – Costs Incurred = $720,000 – $576,000 = $144,000
Step 4: Determine billing position
Billing Position = Billings to Date – Earned Revenue = $780,000 – $720,000 = $60,000 overbilled
What this tells you: You’ve billed $60,000 more than the work you’ve completed. That $60,000 is a liability — you owe the client that much in future performance. Your actual earned profit so far is $144,000, which is on track for the $240,000 estimated profit (60% complete x $240,000 = $144,000). This job is healthy.
Step 5: Check for margin fade
Original estimated margin: $240,000 / $1,200,000 = 20.0%
Current earned margin: $144,000 / $720,000 = 20.0%
No margin fade — the job is tracking exactly to estimate. If the earned margin had dropped to, say, 16%, that would signal $48,000 in margin erosion that you need to investigate before the job finishes.
Critical check: Run this calculation every month on every active project. If your percent complete jumps from 60% to 62% but your costs jump from $576,000 to $620,000, your estimated total cost just increased from $960,000 to $1,000,000 — and your estimated profit dropped from $240,000 to $200,000. Catching this at 62% complete gives you time to fix it. Catching it at 95% complete means you just lost $40,000.
Here’s a complete WIP schedule showing four active projects — this is what your bonding company, bank, and CPA want to see:
| Project A: Medical Office | Project B: Restaurant | Project C: Warehouse | Project D: School Addition | |
|---|---|---|---|---|
| Contract Value | $1,200,000 | $485,000 | $2,100,000 | $875,000 |
| Estimated Total Cost | $960,000 | $400,000 | $1,680,000 | $700,000 |
| Estimated Gross Profit | $240,000 | $85,000 | $420,000 | $175,000 |
| Est. Gross Margin | 20.0% | 17.5% | 20.0% | 20.0% |
| Costs Incurred to Date | $576,000 | $340,000 | $504,000 | $665,000 |
| Percent Complete | 60.0% | 85.0% | 30.0% | 95.0% |
| Earned Revenue | $720,000 | $412,250 | $630,000 | $831,250 |
| Earned Gross Profit | $144,000 | $72,250 | $126,000 | $166,250 |
| Billings to Date | $780,000 | $388,000 | $567,000 | $840,000 |
| Over/(Under) Billing | $60,000 | ($24,250) | ($63,000) | $8,750 |
| Billing Position | Overbilled | Underbilled | Underbilled | Overbilled |
Totals across all projects:
Reading this schedule:
For contractors who bid on public work or large commercial projects, bonding capacity is the ceiling on your growth. Your surety company issues bid bonds, performance bonds, and payment bonds based on their assessment of your financial strength — and the WIP schedule is the centerpiece of that assessment.
Bonding underwriters at companies like Travelers, Liberty Mutual, and CNA Surety evaluate your WIP schedule for these specific signals:
1. Fade analysis: They compare your original estimated profit on each job to the current projected profit. If jobs consistently finish with lower margins than estimated, you have a “fade” problem — and your bonding capacity will shrink regardless of your revenue.
2. Overbilling ratio: Total overbillings divided by total equity. If this ratio exceeds 1.0, you have more overbillings than equity — meaning your entire net worth is effectively borrowed from future performance. Most sureties get uncomfortable above 0.5-0.7.
3. Underbilling concentration: Large underbillings on a single project signal collection risk. If 40% of your underbillings are on one job, and that GC goes bankrupt, your balance sheet takes a significant hit.
4. Backlog-to-equity ratio: Total remaining contract value (backlog) divided by equity. Sureties typically cap this at 10:1 to 15:1 for well-managed contractors. WIP distortions can push this ratio out of acceptable range without the contractor even realizing it.
Real impact: A contractor with $5 million in revenue and clean WIP accounting might qualify for a $3-4 million single bond limit and a $10-12 million aggregate program. The same contractor with sloppy WIP — unreconciled overbillings, stale cost estimates, no monthly updates — might max out at $1.5 million single and $4 million aggregate. That’s the difference between bidding on school renovations and being stuck doing residential additions. Your construction bookkeeping fundamentals have to be solid before any of this works.
While every surety has their own underwriting model, the general framework is:
Working Capital + (Net Worth x Multiplier) – Current Backlog Costs = Available Bonding Capacity
A clean WIP schedule directly improves your working capital number (by properly classifying overbillings and underbillings) and your net worth calculation (by accurately recognizing earned profit). Dirty WIP accounting can understate both — costing you hundreds of thousands in bonding capacity.
WIP accounting isn’t just an internal management tool — the IRS has specific rules about how construction contractors recognize income on long-term contracts, and getting it wrong can trigger penalties, interest, or a much larger tax bill than you planned for.
Under IRC Section 460, contractors with average annual gross receipts exceeding $29 million (2024 threshold, indexed for inflation) must use the percentage-of-completion method for tax purposes on contracts that span more than one tax year.
Contractors below the $29 million threshold have more flexibility:
Smart contractors use WIP accounting strategically for tax planning:
Accelerating costs in December: If you’re using POC and want to increase your completion percentage (and thus your deductible costs) before year-end, you can front-load material purchases and subcontractor payments into December. Buying $80,000 in materials on December 28th instead of January 3rd increases your percent complete and shifts more cost recognition into the current tax year.
Monitoring overbilling tax exposure: Under POC, your taxable income is based on earned revenue — not billings. But if your books aren’t properly tracking WIP, your CPA might inadvertently use billings as a proxy for revenue, resulting in a higher tax bill than necessary. On a $2 million project that’s 50% complete with $1.2 million billed, the difference between paying tax on $1.2 million (billings) vs. $1.0 million (earned revenue) is real money.
Year-end WIP review: Have your CPA review your WIP schedule in November — not April. If you wait until tax time, it’s too late to make strategic cost-timing decisions that could defer $50,000-$100,000 in taxable income.
According to the AICPA Audit and Accounting Guide for Construction Contractors, proper WIP reporting is essential not just for financial statement accuracy but for compliance with tax regulations governing long-term contracts.
After working with dozens of construction clients, we see the same WIP mistakes over and over. Every one of these costs contractors real money — either through lost bonding capacity, surprise tax bills, or jobs that look profitable until the final invoice.
The “estimated total cost” column in your WIP schedule isn’t a set-it-and-forget-it number. It needs to be updated monthly based on actual job conditions. A $960,000 estimate made during pre-construction becomes $1,040,000 after the owner adds a mezzanine, the steel price increases 8%, and the electrical sub comes in $15,000 over their bid.
If you don’t update the estimate, your percent complete is wrong, your earned revenue is wrong, and your profit projection is wrong. You’ll show 20% margin on a job that’s actually running at 12%.
Unapproved change orders create a gray area. You’ve done the work (or you’re about to), but the change order isn’t signed. Do you include it in your contract value and cost estimate?
Best practice: Include approved change orders immediately. For unapproved change orders, include the cost side (you’re spending the money regardless) but only include the revenue side if approval is probable (> 75% likelihood based on your history with this client). This conservative approach prevents phantom profit from showing up in your WIP.
When you’re overbilled by $200,000 on a $1 million job, it feels like you’re ahead. But that $200,000 isn’t profit — it’s a timing difference. If you treat the cash from overbilling as available profit and spend it (on a new truck, a bonus, a down payment on equipment), you’re borrowing from the second half of the job. When costs catch up to billings in the final months, your cash flow reverses and you scramble to fund the completion.
A WIP schedule that’s updated once a quarter is three months stale. A job can go from healthy to hemorrhaging in 60 days — a sub walks off, material prices spike, the owner redesigns a section. Monthly WIP reviews catch these problems while there’s still time to course-correct. Quarterly reviews catch them after the damage is done.
Your WIP schedule is a standalone analysis. Your general ledger is your accounting system. These two need to reconcile — the total earned revenue on your WIP should match the revenue on your income statement, and the total overbillings/underbillings should match the liability/asset accounts on your balance sheet. If they don’t, one of them is wrong, and you won’t know which one until your auditor or bonding company points it out.
You don’t need a $50,000 ERP system to run proper WIP accounting. Here’s what works at different revenue levels:
At this level, most contractors run QuickBooks Online Advanced ($200/month) or QuickBooks Desktop Contractor Edition for the general ledger, combined with a well-structured WIP spreadsheet (Excel or Google Sheets) that the bookkeeper or CPA updates monthly.
QuickBooks setup:
Spreadsheet: Your WIP schedule lives in the spreadsheet. Formulas calculate percent complete, earned revenue, and billing position automatically. The bookkeeper manually enters updated cost estimates and billing totals from QuickBooks each month, then posts the WIP adjustment journal entries back to QuickBooks.
At this level, the spreadsheet approach becomes error-prone. Move to an integrated construction accounting platform:
Regardless of software, the WIP process is the same: Every month, compare costs incurred to estimated total costs, calculate earned revenue, compare to billings, and post the adjustment. Software just makes the data collection faster and the reconciliation more reliable.
Don’t let software replace judgment: No software can tell you that your $960,000 cost estimate should actually be $1,040,000. That requires a conversation with your project manager every month: “Are we on budget? What’s changed? What risks are emerging?” The software handles the math. The PM provides the reality check. If your bookkeeping service isn’t having those conversations, your WIP schedule is garbage-in, garbage-out.
If you’re a construction contractor who’s been running without WIP accounting — or doing it annually for your CPA instead of monthly for yourself — here’s the starting point:
Month 1: List every active project with its contract value, estimated total cost, costs incurred to date, and billings to date. Build your first WIP schedule. You’ll probably find surprises — a job you thought was profitable that’s actually fading, or a significant underbilling you didn’t know about.
Month 2: Update every cost estimate with your project managers. This is the hard part — PMs are optimists by nature, and getting honest estimates requires pushing back on “we’re fine” with actual cost data.
Month 3: Establish the monthly rhythm. WIP schedule updated by the 10th of every month. PM review meeting by the 15th. Journal entries posted by the 20th. Bonding company gets updated financials quarterly.
The contractors who take WIP seriously — who update it monthly, who use it to make billing decisions, who bring it to their bonding meetings — are the ones who grow their bonding capacity year over year and take on larger, more profitable projects. The ones who treat it as a once-a-year chore for tax time are leaving money, bonding capacity, and growth on the table.
If you’re not sure where your WIP stands right now, or if your current bookkeeper isn’t producing a monthly WIP schedule, talk to us about construction bookkeeping. We work with contractors from $1M to $10M in revenue who need financials their bonding company actually trusts. You can also use our instant quote tool to see what specialized construction bookkeeping looks like for your company — it takes about 60 seconds.
Get a free quote and see how Steph's Books can save you 40-60% vs hiring in-house.
