Your WIP schedule is the document your surety reads to set your bonding capacity, and the overbilling and underbilling columns are where a renewal quietly starts to go wrong. One overbilled or underbilled job is normal under percentage-of-completion accounting. What flags a surety underwriter is a pattern: overbilling that stays high relative to your remaining backlog, late-stage underbilling that keeps growing on a near-complete job, or one job that holds most of your underbilled balance. An escalation starts, and the bonding consequences run from a first warning to capacity cuts to disallowances to a renewal at risk. This post names the patterns, the carrier data behind them, and how to correct the position on your work-in-progress schedule inside Procore before the renewal meeting.
What overbilling and underbilling patterns actually flag a surety underwriter?
A surety underwriter does not flag a contractor for one overbilled or underbilled month — that swing is ordinary under the percentage-of-completion method, ASC 606's measure of progress for over-time work. Three patterns draw scrutiny: sustained overbilling relative to remaining backlog, late-stage underbilling that is still growing, and single-job concentration in the underbilled balance.
| Pattern | What the WIP schedule shows | Why it flags the surety | Surety's label |
|---|---|---|---|
| Sustained overbilling | The overbilled balance (billings in excess of costs) stays high across two or more WIP cycles, and stays large relative to remaining backlog — a structural position, not a one-month timing blip | Billing ahead of earned revenue props up cash flow and can mask a job that is quietly losing money | Cash-management concern; "job borrow" |
| Late-stage underbilling (aging) | A job is near-complete — the cited Old Republic case ran 97–99% — but the underbilled balance (costs in excess of billings) is growing instead of closing, with costs still landing against disputed or unapproved work | Work this far along rarely collects disputed balances in full; the underbilling reads as a permanent shortfall, not a timing difference | Collectability concern; candidate for disallowance |
| Single-job concentration | One project holds a disproportionate share of the total underbilled balance — for example, the bulk of all costs in excess of billings sitting on one job | If that one collection fails, working capital drops across the whole bonding program at once | Concentration risk |
These are balance-sheet positions: overbilled is billings in excess of costs (a current liability); underbilled is costs in excess of billings (a current asset). For the formula and a worked example, see over/under billing in construction.
On the sustained-overbilling row, "job borrow" is Old Republic Surety's own term for a job overbilled to the point that "the estimated costs to complete the job exceed the remaining unpaid contract balances" (Mike Sanders, AFSB, Old Republic Surety). The broader cash-flow reading in the table above (an overbilled position propping up a fading job) is this post's extension, not the carrier's words.
The surety reads these patterns off the WIP schedule itself, not just the year-end financials. Per Turner Surety & Insurance Brokerage (TSIB), 2026 underwriters want "interim reporting and job-level transparency," and they have "less patience for repeated 'one-time' explanations in WIP schedules" (TSIB, 2026 Surety & Construction Forecast).
What the named carrier data actually shows (not unsourced estimates)
The round-number thresholds quoted around this topic — "10–15% overbilling is uncomfortable," "sureties discount underbillings 20–30%" — are individual practitioners' estimates, not published carrier policy. The most authoritative source on what actually triggers an underbilling action is a case study Old Republic Surety published in the National Association of Surety Bond Producers (NASBP) Pipeline, written by Mahki Abner, AFSB, Associate Underwriter.
Here is the case, in the carrier's numbers. "In a recent analysis by Old Republic Surety, underbillings inflated one contractor's [working capital] by nearly $3 million," overstating the contractor's financial position (Mahki Abner, Old Republic Surety, NASBP Pipeline). One project drove it: 97% complete at year-end, it carried $296,000 in underbillings. Six months later, at 99% complete, underbillings had grown to $419,000 despite ongoing losses. "This trend indicated a low likelihood of collection, leading to the disallowance of these amounts from the contractor's [working-capital] calculation" (NASBP Pipeline).
Old Republic published a behavior, not a threshold: a near-complete job whose underbilling keeps climbing despite losses earns a disallowance.
The mechanism is documented by the Fedeli Group. Its year-end balance-sheet table — written by Kevin Keller, a former manager at several national surety companies — lists how a surety adjusts each current asset to compute adjusted working capital. The line that matters here: "Under Billings — 100% excluded from working capital if from unapproved change orders or profit fade" (Fedeli Group). Underbillings are not always stripped out. Underbillings that trace to unapproved change orders or profit fade (the two root causes of the patterns above) are.
The disallowance is expensive: the bonding multiple applies to whatever working capital survives it. SuretyCFO puts the rule of thumb at roughly 10x adjusted working capital, with aggregate programs commonly running a 10–20x band that varies by surety (SuretyCFO). At 10x, a $3 million disallowance like Old Republic's removes about $30 million of bonding capacity; at the top of the band, closer to $60 million. That underbilling didn't stay on one job. It moved the ceiling on the whole program.
The surety's escalation sequence: from first warning to renewal-at-risk
A surety flag does not immediately cancel your bonding program. It starts an escalation sequence. The four-stage sequence below is WIP Ready's composite model of how surety escalation typically runs — not a carrier-published timeline; sureties vary in order and pace.
- First warning — informal flag at the annual review. The underwriter raises the pattern in conversation: "Your underbilling on Lincoln HS Renovation has grown three periods in a row." (Illustrative.) Nothing changes on paper yet, but the file is flagged for monitoring. Per TSIB, 2026 underwriters have "less patience for repeated 'one-time' explanations" (TSIB).
- Capacity reduction — a limit trimmed at renewal. If the pattern persists into the next cycle, the underwriter reduces either the single-job limit (the largest bond for any one project) or the aggregate limit (total bonded backlog allowed at once). You still have a program; it is just smaller — the most common first formal action.
- Disallowance — underbillings excluded from adjusted working capital. The underwriter removes the flagged underbillings from the working-capital base, as Old Republic did. Where a stage-2 trim is the underwriter's judgment call, a disallowance is the formal exclusion that mechanically caps capacity. Say Meridian Construction Group carries $1 million in late-stage underbillings the surety does not believe will collect. (Illustrative.) Disallow the $1 million, apply a 10x aggregate multiple, and the program shrinks by roughly $10 million (SuretyCFO).
- Renewal-at-risk — program on conditional status. If the pattern survives two consecutive renewals, the carrier puts the program on a watch list. Renewal becomes conditional on a corrective-action plan, an agreed timeline to close the flagged underbillings, or a surety-approved review by a construction CPA.
Why is the surety this selective in 2026? Capacity is ample; qualification is not. "Capacity isn't changing — it's selectivity," is how TSIB frames the year (TSIB). The soft stretch is reversing: the industry's direct incurred loss ratio sat at a 10-year-best 20.5% through Q3 2025 on a wave of IIJA-funded work, and that federal tailwind expires in September 2026 (Construction Equipment Guide / AM Best). For how the underwriter reads every column behind these patterns, see what your surety underwriter reads in each line of your WIP; for the broader red-flag set beyond billing, see the five WIP patterns that cut bonding capacity.
How to fix the billing position in Procore before the renewal meeting
The escalation only advances if the pattern persists, so the work is to make it stop persisting before the file goes out. Correcting it takes three steps in Procore: re-forecast the ETC on the flagged job, verify the billing schedule against earned revenue, and re-run the WIP. None of the SERP results on this topic walk this through, because none of them is Procore-native.
Step 1 — Re-forecast the Estimate to Complete (ETC) for the flagged job. In Procore, open the project's Budget module and work under Forecast to Complete. The PM or project accountant updates the remaining cost estimate for each cost code. If a late-stage underbilling is driven by an unapproved change order or a scope dispute, the ETC on that work should reflect the realistic collection scenario, not the original bid. How the number moves depends on the line's Forecast to Complete method — Automatic, Manual, Monitored Resources, or a manual override — so see how each Procore Forecast to Complete method changes the WIP number.
Step 2 — Verify the billing schedule against earned revenue. Cross-check the Billed to Date figure in the project's Prime Contract against the earned revenue computed from the updated ETC. If the job is overbilled (billed more than earned), decide whether a billing adjustment or credit is warranted before the renewal package is assembled. An overbilled position the surety can see and you cannot explain as a timing item reads as a cash-management flag.
Step 3 — Re-run the WIP. With the ETC current in Procore, pull the updated schedule and confirm three things: the late-stage underbilling balance is closing rather than growing; any sustained overbilling ties to a timing item, like an invoice cut-off, that clears next period; and no single job holds a disproportionate share of the total underbilled balance. If the pattern has not materially moved, the correction is not finished — do not put the WIP in front of the surety until it explains itself. Then check the whole file against the self-audit checklist you run before the annual review.
One honest caveat. WIP Ready computes the over/under position from Procore's cost and billing data, but the PM owns the ETC; WIP Ready never generates it. If an estimate is revised to make the WIP look corrected rather than to reflect the job, the surety's follow-up review will find the gap between the revised WIP and the next set of job financials. Fix the number to make it true, not presentable.
Frequently asked questions
What WIP overbilling pattern triggers a surety flag? Sustained overbilling — an overbilled balance that stays high across two or more WIP cycles relative to remaining backlog, not a one-off month — because a persistent overbilled position can mask a job billing ahead of earned revenue, what surety people call "job borrow" (Old Republic Surety).
When does late-stage underbilling become a surety problem? When it grows on a near-complete job. Old Republic Surety traced one from 97% complete with $296,000 in underbillings to 99% complete with $419,000 six months later despite losses, then disallowed it from working capital (Mahki Abner, NASBP Pipeline, 2025).
What is the surety's escalation sequence for WIP billing problems? First warning at the annual review, then a capacity reduction at renewal, then disallowance of the flagged underbillings from adjusted working capital, then renewal-at-risk on conditional status with a required corrective-action plan.
How does sustained overbilling affect bonding capacity? It does not inflate working capital (it sits in current liabilities), but a persistent overbilled position reads as a cash-management and profit-fade signal the underwriter can penalize at renewal (TSIB).
What is "disallowance" on a surety WIP review? A surety stripping an item out of adjusted working capital because it doubts it will collect — the Fedeli Group lists "Under Billings — 100% excluded from working capital if from unapproved change orders or profit fade" (Kevin Keller, Fedeli Group).
How do I correct overbilling or underbilling in Procore before a surety meeting? Re-forecast the ETC under Procore's Budget > Forecast to Complete, cross-check Billed to Date in the Prime Contract against earned revenue, then re-run the WIP and confirm the late-stage underbilling is closing and no single job dominates the underbilled balance.
How much can underbilling inflate a contractor's adjusted working capital? By nearly $3 million in one named Old Republic / NASBP case — and at a ~10x bonding multiple, that working-capital reduction can pull roughly $30–$60 million out of a bonding program (SuretyCFO).
How WIP Ready helps
Most of these patterns trace back to one weak input: an ETC that is stale, anonymous, or revised under renewal pressure. WIP Ready collects each PM's Estimate to Complete on their phone — with a name, a timestamp, and a note on every figure — and computes the over/under billing position from your Procore cost and billing data. Every number traces back to a Procore field or a timestamped submission, so when the underwriter asks why an underbilling grew, you have the attribution, not a verbal explanation. It is a read-only layer over Procore: it never replaces your accounting system, and it never invents the ETC; the PM still owns that number, which keeps the WIP defensible with a surety. If your next renewal file is why you are reading this, that is the part worth a look: wipready.com.
