Business, Mid-Market & Industrial

How to Underwrite a Construction or Trades Contractor

Underwrite a construction contractor by analyzing the work-in-progress schedule: backlog, estimated margins, percentage complete, and over and under billings. Then test historical margin fade and bonding capacity. The metrics that matter most are backlog coverage, gross margin consistency from bid to completion, net over and under billings, and working capital relative to bonding requirements.

What makes construction contractor underwriting different

A contractor's revenue comes from projects recognized over time using percentage-of-completion accounting, which relies on estimates of total cost. If estimates are wrong, margins fade as projects progress, and profit recognized earlier must be reversed. The work-in-progress schedule shows each job's contract value, cost to date, estimated cost to complete and billing status, making it the most important underwriting document. Underbillings can signal cost overruns or disputes, while overbillings reflect cash collected ahead of work. Retainage held by customers ties up cash. Bonding capacity limits project size, and sureties assess working capital and net worth. Labor availability, subcontractor performance and safety records also matter.

Lenders focus on working capital, WIP quality, backlog and the surety relationship. They often provide working capital lines with borrowing bases that exclude retainage, bonded job receivables and older balances. The surety acts as a parallel underwriter, and losing bonding capacity can stop a contractor from bidding new work, so lenders rarely act without understanding the surety's view. Equity buyers value contractors for backlog, repeat customer relationships, specialty trade capabilities and licensed staff, and look for margin improvement through better estimating and project controls. Equity may pay for backlog growth, while lenders focus on the downside from a single bad job and the liquidity needed to finish it.

Key metrics

Backlog coverage

Contracted backlog relative to annual revenue shows revenue visibility.

Gross margin fade

Comparing estimated margin at bid to final margin shows estimating accuracy.

Net over and under billings

Underbillings can signal cost overruns; overbillings provide cash but represent obligations to complete work.

Working capital

Sureties and lenders use working capital to set bonding and credit limits.

Sureties often relate single job and aggregate bonding limits to a multiple of working capital and net worth.

Retainage receivable

Retainage is cash withheld until project completion and can strain liquidity.

Customer concentration

Contractors can depend on a few general contractors, owners or public agencies.

How to underwrite it, step by step

Obtain WIP schedules for the past several years and reconcile them to financial statements.
Compare estimated and final margins on completed jobs to measure fade.
Analyze current backlog by customer, project type and expected margin.
Review over and under billings by job and investigate large underbillings.
Assess retainage receivable and aging of receivables.
Review bonding capacity and surety relationship.
Evaluate safety record, labor availability and key project managers.
Size debt and structure working capital facilities based on WIP and backlog.

Due diligence checklist

WIP schedules for three to five years
Completed contract reports
Backlog report
Accounts receivable and retainage aging
Surety letters and bonding capacity
Major contracts and change orders
Claims and dispute log
Safety records and EMR
Equipment list
CPA-reviewed or audited financial statements
Key personnel resumes

Key risks and mitigants

Margin fade on large fixed price projects.

Measure historical fade on completed jobs, haircut margins on current backlog and limit exposure to any single job relative to equity.

Disputed change orders or claims tied up in underbillings.

Review the claims log, interview project managers and exclude disputed amounts from collateral and EBITDA.

Surety reduces bonding capacity after the ownership change.

Engage the surety early, confirm the new indemnity structure and maintain working capital covenants consistent with surety requirements.

Key estimator or project managers leave.

Use retention agreements, rollover equity or earnouts and assess management depth below the owner.

Slow payment and retainage strain liquidity.

Analyze receivable and retainage aging by customer and size the working capital line for peak needs.

Labor shortages or wage escalation on fixed price contracts.

Review escalation clauses and labor availability, and stress labor cost on backlog.

Typical financing and deal structure

Construction contractors typically use bank working capital lines secured by receivables, with borrowing bases that exclude retainage and older balances, plus equipment loans for heavy machinery. Acquisitions may use SBA 7(a) for smaller contractors or senior and unitranche debt for larger firms. Sellers often provide seller notes or earnouts tied to backlog completion and margins. Sureties may require indemnity agreements from owners and minimum working capital. Covenants include minimum working capital, net worth and leverage, and lenders coordinate with sureties to avoid conflicts over collateral. Lenders typically want to see CPA-reviewed or audited statements with WIP schedules every year and often quarterly WIP reporting.

Red flags

Large underbillings on several projects.
Consistent margin fade from bid to completion.
Surety reducing bonding capacity.
Significant unresolved claims or change order disputes.
Backlog declining or concentrated in a few large jobs.

Frequently asked questions

What is a WIP schedule?

A work-in-progress schedule lists each active project with contract value, costs to date, estimated costs to complete, percentage complete, billings and gross profit. It shows whether projects are profitable and whether billing is ahead of or behind work performed. Lenders, sureties and buyers rely on it as the central document for contractor underwriting.

What are over and under billings?

Overbillings occur when a contractor bills more than the revenue earned based on percentage complete, while underbillings occur when it bills less. Overbillings bring in cash early but represent work still owed. Large underbillings can indicate cost overruns, unapproved change orders or billing problems and often warrant closer review.

How does bonding affect a contractor's value?

Many public and large private projects require performance and payment bonds. A contractor's bonding capacity, set by its surety based on working capital, net worth and track record, limits the size and number of projects it can pursue. Strong bonding capacity supports growth and value, while reduced capacity can limit future revenue.

Why is margin fade important?

Margin fade occurs when a project's final profit is lower than estimated at bid or earlier in the job. Consistent fade suggests weak estimating or project management and means current backlog margins may be overstated. Underwriters compare bid and final margins on completed jobs to judge estimate reliability.

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Educational content, not investment, credit, legal or tax advice. Benchmarks are common practitioner rules of thumb and vary by lender, market and cycle.