TL;DR: Bonding capacity isn't a paperwork problem for the office to handle. It's a bidding input. If you don't know your single and aggregate limits before letting day, you're not really running a bid strategy — you're hoping.

Most estimators treat the bid bond like a form. Call the agent, get the bond, staple it to the proposal, move on.

Then one day the agent says no.

Not on a job you wanted to skip. On the one you built your whole third quarter around.

Here's what's actually happening behind that phone call, and why it belongs in your bid/no-bid conversation instead of your paperwork checklist.

What a Bid Bond Actually Promises

A bid bond isn't a guarantee that you'll build the work. It's a guarantee about what happens between bid opening and contract signing.

Specifically: if you're the low, responsive, responsible bidder, you'll honor your bid price, sign the contract, and furnish the required performance and payment bonds.

That's it. Three promises, all of them about showing up.

The surety is putting its name behind those promises, which means it has already decided you're good for the performance and payment bonds on the back end. A bid bond is really a preview of a much bigger underwriting decision.

What You Actually Forfeit If You Walk

This one gets misunderstood constantly.

Bid guaranty is usually required at 5% of the bid — that's the standard on most public work, including state DOT lettings. WSDOT, for one, requires the bid bond be at least 5% of the bid amount.

But 5% is the ceiling, not the check.

If you refuse to sign, the owner's damages are the difference between your bid and what they end up paying the contractor who does take the job — capped at the penal sum of your bond.

So: you bid $4.2 million, you walk, and the owner awards to the next bidder at $4.35 million. Their damage is the $150,000 difference. Your 5% penal sum was $210,000, so the claim lands inside the cap and you're on the hook for $150,000.

Two things follow from that.

One, a bid mistake you catch before award is a much cheaper conversation than one you catch after. Two, the money is the smaller problem. The claim goes on your surety file forever. Character is one of the three things underwriters grade you on, and "walked away from an award" is a hard stain to explain in the next renewal meeting.

The Two Numbers That Run Your Bid Calendar

Every bonded contractor has two limits assigned during underwriting. Know both of them by heart.

Single limit

The largest bond your surety will write on one contract. A common rule of thumb is roughly 10x working capital or 5x net worth, whichever is less.

Read that again. Whichever is less. Plenty of contractors have plenty of net worth tied up in iron and dirt and almost no working capital, and then wonder why their single limit is small.

Aggregate limit

The total bonded backlog the surety will carry across all your open jobs at once. Typically 2 to 4 times the single limit, depending on your track record and how mature your accounting is.

The aggregate limit is the one that sneaks up on people. Every job you win consumes capacity until it's complete and closed out. Win three medium jobs in April and the big one you actually wanted in June may be unbondable — not because you can't build it, but because you spent the room.

That's a bidding decision, and it should be made on purpose.

Where Bonds Are Required in the First Place

Federal work runs under the Miller Act: performance and payment bonds are required on construction contracts over $150,000, both at 100% of the contract value. Between $35,000 and $150,000, payment protection is required but the contracting officer has discretion and may accept alternatives. FAR 28.102-1 was updated under FAC 2026-01, effective March 13, 2026, and those thresholds stand.

States run their own "Little Miller Acts" with their own thresholds and their own quirks. Your DOT's standard specifications will spell out the bid guaranty form, the amount, and the deadline to furnish the P&P bonds after award. Read it once per state per year — they change.

Premium on the performance bond generally runs 1% to 3% of contract value for established contractors in the standard market. Bid bonds themselves are typically issued at little or no direct cost, which is exactly why people forget they represent a real credit decision.

And put the premium in the estimate as its own line. Not in overhead, not in the fudge. It's a cost of the work.

What Underwriters Are Actually Grading

Sureties evaluate three things. They've been called the three C's forever because the framing holds up:

• Character — your reputation, your integrity, how you handle bad news. Do you call the owner before the problem shows up, or after?
• Capacity — your organizational and technical ability to build the work profitably. Experience in the work type, management depth, crews, equipment.
• Capital — equity, working capital, low debt, and cash flow discipline.

Here's the part estimators should care about most: your WIP schedule is a surety document.

Large underbillings on late-stage jobs signal profit fade that hasn't been booked yet. When an underwriter sees that, they read your working capital and net worth as overstated — and capacity comes down.

Which means sloppy cost-to-complete estimates don't just distort your financials. They shrink the size of job you're allowed to chase.

How to Actually Grow Capacity

None of this is fast, and all of it is boring:

• Leave money in the business. Retained earnings are the cheapest capacity you can buy.
• Upgrade your financial statements. Moving from compiled to CPA-reviewed to audited, on percentage-of-completion accounting, moves the needle with underwriters.
• Get your WIP right and get it monthly. Accurate cost-to-complete beats optimistic cost-to-complete every single time.
• Bill on time and collect. Working capital is the multiplier on your single limit — aging receivables are a direct tax on it.
• Bond your subs when the risk warrants it, and tell your surety you did.
• Treat your agent and underwriter like partners. Bring them the bad job before they find it. Character is the C that's hardest to rebuild.

If you're a smaller contractor and the standard market won't get you where you need to be, the SBA's Surety Bond Guarantee Program backs 80% to 90% of the surety's loss and supports contracts up to $9 million, or up to $14 million on federal contracts when a contracting officer certifies the need.

Make Capacity Part of the Bid/No-Bid Call

The 2026 surety market has been tightening, and ABC's Construction Backlog Indicator has been climbing — which means more contractors are chasing capacity at the same time underwriters are getting choosier. Assuming you'll have the same room you had last year is a bad assumption.

So put it in the process:

• Know your remaining aggregate room before every letting, not after
• Rank the quarter's opportunities and decide which ones deserve the capacity
• Confirm bondability early on anything near your single limit — before you spend 80 hours estimating it
• Carry bond premium as a real line item
• Watch bid consortiums and joint ventures as a legitimate tool for jobs above your limit

At Edgevanta, the whole point of getting quantities and specs out of the way faster is so your team spends its time on decisions like this one — which jobs are worth your capacity — instead of retyping numbers.

The bottom line: your surety doesn't decide how much work you can build. It decides how much work you're allowed to bid. Manage that number like it's a resource, because it is.