Bid Bond
Also known as: bid guarantee, bid security
A bid bond is a form of surety bond that a contractor submits along with its proposal on a construction or supply project. It is a three-party guarantee — among the contractor (principal), the project owner (obligee), and the surety — that the contractor has submitted its bid in good faith, will stand behind the price quoted, and, if selected, will sign the contract and provide the follow-on bonds the job requires. Public agencies and many private owners require a bid bond, typically valued at 5% to 20% of the bid amount, on every solicitation.
It matters because it protects the owner from the cost and delay of a bidder who wins the job and then walks away, forcing the owner to re-award to the next-lowest — and usually more expensive — bidder. If that happens, the surety pays the owner the difference between the defaulting bid and the replacement bid, up to the bond's penal sum, and the contractor must reimburse the surety under its indemnity agreement. For the contractor, being bondable is a competitive credential: obtaining a bid bond signals to the owner that a surety has already vetted the firm's finances, experience, and capacity to complete the work.
A practical nuance is that the bid bond is the front door to the full bond program. A surety will not issue a bid bond unless it is prepared to issue the corresponding performance bond and payment bond should the contractor win, because backing the bid commits the surety to backing the contract. Small contractors should therefore establish surety credit and a bond line before chasing bonded work, understand that the bid bond premium is usually nominal or free (the real underwriting cost sits in the performance bond), and confirm the exact bond percentage and format each solicitation demands so a bid is not rejected as non-responsive.
Real-world scenario
Cornerstone Grading & Site LLC, a mid-sized excavation contractor in Ohio, wanted to bid on a county project to rebuild a stormwater detention basin. The bid documents required a bid bond equal to 5% of the base bid as the owner's assurance the contractor would sign the contract if selected. Cornerstone's estimator priced the job at $2,340,000, so the required bid bond penal sum was $117,000 (5% of $2,340,000). Because the bond was tied to Cornerstone's broader surety program, the surety charged $0 in premium for the bid bond itself and added only a $250 processing fee.
To qualify, the surety underwrote Cornerstone's balance sheet: $6,800,000 in annual revenue, $450,000 in working capital, $1,200,000 in net worth, and a standby bank line of credit of $500,000. The surety approved a single-job limit of $3,000,000 and an aggregate program of $10,000,000. Cornerstone submitted the low bid at $2,340,000; the next bidder came in at $2,528,000.
Then Cornerstone realized it had omitted $188,000 of dewatering costs and tried to walk away. The county awarded to the second bidder and demanded the $188,000 difference. The bid bond capped the surety's exposure at the $117,000 penal sum, so the surety paid the county $117,000 and, under its indemnity agreement, recovered that $117,000 plus $12,000 in legal costs from Cornerstone. The lesson: on award Cornerstone would also have needed a performance bond and payment bond, typically priced near $23,400 at roughly $10 per $1,000 of contract value.
How it affects your premium
Bid bonds are usually issued at little or no direct premium because the surety's real underwriting is for the performance bond and payment bond that follow on award. The factors below drive whether a surety will issue the bid bond and how much bonding capacity it extends:
- Contractor financial strength — working capital, net worth, and bank lines are the primary levers; thin balance sheets get low single-job and aggregate limits.
- Penal sum size — the bid bond amount (often 5%–10% of the bid) determines the exposure the surety must reserve against the contractor's remaining capacity.
- Project size and type — a large or complex public job stresses the follow-on surety obligations more than a small, routine one.
- Experience with similar work — a track record on comparable scopes reduces the risk the contractor cannot deliver at the bid price.
- Backlog and current bonded work — heavy uncompleted backlog consumes aggregate capacity and can trigger a decline.
- Public vs. private owner — federal jobs require a Miller Act bond structure, while many states use a license and permit bond or their own statutory forms, each shaping the surety's commitment.
- Personal and corporate indemnity — the strength of the signed indemnity and any collateral affects both approval and the cost of the follow-on bonds.
Common misconceptions
Myth: A bid bond guarantees I'll get paid for the work if I win.
Reality:
No. A bid bond only guarantees you will sign the contract and post the required final bonds if awarded. Payment to your subcontractors and suppliers is guaranteed by a separate payment bond, and your completion of the work by a performance bond.
Myth: The bid bond just costs a small percentage of my bid as premium.
Reality:
The 5%–10% figure is the penal sum (the maximum the surety could pay the owner), not your cost. Sureties typically issue the bid bond for a nominal fee or free, because their underwriting and pricing focus on the follow-on surety bonds.
Myth: A bid bond is basically the same as a certified check or cashier's check.
Reality:
They serve the same bid-security purpose, but a bond preserves your cash and is a three-party contract surety obligation, whereas a certified check ties up real funds until the award is finalized.
Myth: If I win but back out, I only lose the bid; there's no other liability.
Reality:
If you refuse to sign, the surety pays the owner up to the bond amount, then recovers every dollar from you under your indemnity agreement, plus legal fees.
Frequently asked questions
How much does a bid bond cost?
Most sureties issue bid bonds at no premium or for a small flat fee (often $0–$250) because their pricing is built into the performance bond and payment bond you buy if you win the job.
What is the difference between a bid bond and a performance bond?
A bid bond guarantees you'll sign the contract and post final bonds if selected; a performance bond guarantees you'll actually complete the awarded work per the contract terms.
What happens if I win the bid but can't get bonded?
The owner treats it the same as backing out: they can claim your bid bond and award to the next bidder, so confirm your surety will support the full surety program before you bid.
Are bid bonds required on federal projects?
Yes. Federal construction contracts over $150,000 require performance and payment bonds under the Miller Act, and the Federal Acquisition Regulation requires a matching bid guarantee (bid bond); many state and local jobs impose similar requirements.
Do I need good credit to get a bid bond?
Sureties weigh your company's financials, experience, and backlog most heavily, but the owner's personal credit and a signed indemnity agreement are also reviewed, especially for smaller contractors.
Sources cited
Need bid bond coverage?
Compare quotes from 10+ commercial insurance carriers in 5 minutes. Free, no contact info required.
Get My Quotes →