By Daniel Jahn, CPA — Contractor’s Ledger
A WIP schedule — short for Work in Progress schedule — is one of the most important financial documents a specialty trade contractor produces. Yet most contractors either don’t have one, don’t know what it’s supposed to show, or are producing one that their surety underwriter can’t use.
This guide explains exactly what a WIP schedule is, why it matters, and what goes into one that actually works for your bonding company, your bank, and your own decision-making.
What Is a WIP Schedule?
A WIP schedule is a report that shows the financial status of every open (in-progress) construction contract at a given point in time. It answers three core questions for each active job:
- How much of the work is complete? (expressed as a percentage)
- How much have you billed? (compared to what you’ve earned based on that percentage)
- Are you overbilled or underbilled?
The over/underbilled position is the heart of a WIP schedule. It tells you — and your bonding company — whether you’re running ahead of your billing or behind it on each project.
Why WIP Schedules Matter
For Bonding and Surety
Surety underwriters use WIP schedules to assess the risk profile of a contractor’s open work. Specifically, they want to see:
- How many open contracts you’re managing simultaneously
- Whether you’re consistently overbilling (collecting money you haven’t earned yet — a liability)
- Whether you have large underbilling positions (an asset, but a question mark on whether you’ll collect)
- The total value of your open contract backlog
A contractor’s WIP schedule is as important as their balance sheet to most surety underwriters. Without a current, accurate WIP schedule, many bonding agents simply can’t provide the coverage you need.
For Job Profitability
A well-maintained WIP schedule catches problems while there’s still time to fix them. If a job is 60% complete but only 45% of the budget remains, you’re trending over budget — and the WIP schedule will show that before the job closes.
For Bank Relationships
Banks extending lines of credit to contractors increasingly want to see WIP schedules. They want to know your backlog is real, your billing is appropriate, and your overbilled position isn’t masking a cash flow problem.
How Is a WIP Schedule Calculated?
Here’s the basic structure of a WIP schedule for a single contract:
Key inputs per job:
- Revised contract value (original contract + approved change orders)
- Total estimated cost at completion
- Costs incurred to date
- Total billed (including retainage) to date
Calculations:
- Percentage complete = Costs incurred to date ÷ Total estimated cost at completion
- Earned revenue = Percentage complete × Revised contract value
- Overbilling = Billed to date − Earned revenue (when billed exceeds earned)
- Underbilling = Earned revenue − Billed to date (when earned exceeds billed)
A WIP schedule rolls up these calculations across all open contracts, giving you a total overbilled and total underbilled position for the company at a point in time.
Overbilling vs. Underbilling — What’s the Difference?
Overbilling means you’ve collected more cash than you’ve earned based on percentage of completion. This is sometimes called “front-loading.” While it’s good for cash flow in the short term, a large overbilling position is a liability — you owe that work to the customer. Surety underwriters flag heavy overbilling as a risk signal.
Underbilling means you’ve performed more work than you’ve billed for. This is technically an asset — you’re owed that money — but it can also signal a billing process problem or a job that’s running behind schedule. Persistent underbilling across multiple jobs is a cash flow warning sign.
Neither position is inherently good or bad in small amounts. A WIP schedule makes the position visible and quantifiable.
What Surety Underwriters Look For
When a surety underwriter reviews your WIP schedule, they’re looking at:
- Total open contract value relative to your balance sheet size (your “backlog”)
- Gross overbilling as a percentage of contract values
- Estimated profit on open contracts — is the work profitable?
- Largest single contracts — concentration risk
- Completed contract profitability — how did your recently closed jobs perform versus estimate?
A WIP schedule that shows consistent profitability on completed work, reasonable overbilling/underbilling positions, and a backlog that matches your labor capacity is what gives surety underwriters confidence to increase your bond line.
How Often Should You Prepare a WIP Schedule?
At minimum, quarterly. If you’re in active bonding conversations, pursuing prequalification with larger GCs, or have bank reporting requirements, monthly is better.
The WIP schedule only has value if it’s current. A WIP schedule prepared six months ago tells a surety underwriter nothing useful about where you stand today.
How Contractor’s Ledger Helps
We prepare WIP schedules for specialty trade contractors on a regular cadence — monthly or quarterly depending on your needs. We format them to the standard that surety underwriters expect, maintain the cost-to-complete estimates with your input, and integrate the WIP schedule into your broader monthly financial reporting.
For contractors who have never had a WIP schedule or who have one that their bonding agent keeps rejecting, this is usually one of the highest-value things we do. A properly prepared WIP schedule has helped our clients increase their bond lines and qualify for larger projects.
See our WIP schedule preparation service or get a free financial review to talk through your current situation.
Daniel Jahn is a licensed CPA and founder of Contractor’s Ledger, a construction accounting firm serving specialty trade contractors nationwide.
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