Bonding capacity isn't negotiated — it's calculated, from three or four numbers in your financial statements. What the surety looks at, how they discount what you show them, and how to grow capacity on purpose.
A surety isn't an insurer betting on odds — it's a guarantor betting that you'll finish your jobs. So the underwriter reads your financials like a credit officer: how much liquid cushion do you have, how much of the business do you actually own, and do your jobs finish at the margins you claim? Those answers become your single and aggregate bonding limits.
Which means bonding capacity is an accounting outcome. Two contractors with identical trucks, crews, and backlog can have wildly different programs — because one shows up with clean, percentage-of-completion statements and a current WIP schedule, and the other shows up with a cash-basis P&L and a shrug.
Current assets minus current liabilities — the money available to absorb a bad month without missing payroll. It's the surety's north star, and the informal industry rule of thumb is that aggregate bonding capacity runs somewhere around 10–20× working capital, depending on the surety, your history, and everything else on this page.
But here's what surprises contractors: the surety doesn't use your working capital number. They compute analyzed working capital, discounting anything they doubt they could turn into cash:
A contractor with $800K of book working capital can easily analyze out at $500K — and their bonding program shrinks to match.
Net worth tells the surety how much of the company's risk the owner actually carries, and the trend tells them what the owner does with profits. Earnings retained in the business grow capacity; heavy distributions that strip the balance sheet each year cap it. Sureties also watch for owner loans masquerading as equity and may ask to subordinate them. If growing bonded work is the plan, leaving money in the company is part of the price.
The underwriter reads your WIP schedule the way a poker player reads faces:
Blackline delivers POC-basis reporting, monthly WIP schedules, and bonding & lender support — the package underwriters want, every month.
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