Bid bond

How a bid bond works

A bid bond is a promise made by three parties. The principal is the bidder. The obligee is the owner or public agency asking for bids. The surety is the company that guarantees the bidder will keep its word. If the bidder wins and then won’t sign the contract or can’t provide the required performance and payment bonds, the owner can make a claim on the bid bond.

The bid documents set the bond amount, called the penal sum, usually as a percentage of the bid or a fixed dollar amount. The penal sum is the most the surety will pay, not a fee. The bond also has a deadline built in: bids can typically not be withdrawn for a period after bid opening that the bid documents set, and the winner must sign and deliver its bonds within a set time after award.

How much the owner can collect depends on the bond’s wording and the law. Some bonds limit recovery to the owner’s actual loss, often the extra cost of awarding the job to the next bidder, up to the penal sum. Others treat the full penal sum as forfeited. Read the bond form in the bid package before you sign it.

A bid bond isn’t insurance for the bidder. If the surety pays the owner, it will look to you for repayment under the indemnity agreement you, and often the company’s owners personally, signed when you got bonded. The real value of the bid bond to the owner is the surety’s vetting: a surety that writes your bid bond is signaling it expects to write your final bonds if you win.

Bid bonds and other forms of bid security

Bid documents usually say which forms of bid security they accept. A bid bond is the most common on public work, but it isn’t always the only choice.

Some bid packages also ask for a letter from the surety stating that it will provide the performance and payment bonds if you win. Follow the instructions exactly. A bid with the wrong form of security, an unsigned bond or a bond for the wrong amount can be rejected as nonresponsive.

Why bid bonds matter to each party

For contractors

A bid bond is your ticket into bonded work, and it holds you to your number. If you find a mistake after bid opening, you face a hard choice: build the job at a loss, or walk away and risk a claim your surety will expect you to repay. Either way, your surety will notice, and future bonding can get harder.

For owners and public agencies

A bid bond screens out bidders who couldn’t get bonded for the full job and protects the owner if the winner backs out. Without it, the owner might have to rebid the project or award it to a higher bidder with no recovery for the difference.

For smaller contractors moving into public work

Your first bid bond usually takes the most work. The surety is underwriting the whole job, not just the bid, so expect questions about your financial statements, work in progress and experience on jobs of this size.

How to get and use a bid bond step by step

1. Find a surety agent who works with contractors before you need a bond, and share your financial statements, work history and current backlog.
2. Read the bid documents for the bond amount, the required form, the withdrawal period and the deadline for final bonds after award.
3. Confirm with your agent that the surety will support the final performance and payment bonds at your bid price.
4. Order the bid bond early, giving the agent the project name, owner, bid date and estimated bid amount.
5. Check your takeoff and pricing twice, ideally with a second person reviewing the largest lines.
6. Before submitting, check that the bond is signed by you and the surety, uses the right form, and names the correct owner and project.
7. If you win, deliver the signed contract and final bonds before the deadline in the bid documents.

If you discover a serious error after bid opening, call your surety agent and a construction attorney right away. Some states have procedures for withdrawing a bid over a clear clerical mistake, but they come with strict conditions and timing, so check your state before assuming one applies.

Bid bond example with numbers

Say a contractor submits a low bid of $480,000 on a municipal building project. For illustration, the bid documents require a bid bond equal to 10% of the bid amount, so the penal sum is $480,000 × 10% = $48,000. The contractor wins the award, then refuses to sign the contract.

The owner awards the job to the bidder with the next price up. What the owner loses is roughly the difference between the two bids, and the table shows two versions of that next bid.

In the first scenario, the difference is $505,000 − $480,000 = $25,000, which is less than the $48,000 penal sum. Under a bond limited to the owner’s actual loss, the claim would be about $25,000. Under a bond that treats the full amount as forfeited, it could be $48,000. In the second scenario, the difference is $545,000 − $480,000 = $65,000, but the surety’s payment is capped at $48,000. Whether the owner can pursue the bidder for the remaining $17,000 depends on the bond’s wording and the law.

In both cases, whatever the surety pays, the contractor is expected to repay under the indemnity agreement, along with the surety’s costs where the agreement allows. The cheaper path is almost always finding the error before the bid goes in.

Common bid bond mistakes

• Waiting until bid week to contact a surety for the first time.
• Submitting a bond for the wrong amount, on the wrong form, or without every required signature.
• Treating the bid bond as a formality without reading what it obligates you to do.
• Bidding a job larger than your surety will support with final bonds.
• Rushing the estimate to make the deadline, then finding the error after bids are opened.
• Assuming a mistaken bid can always be withdrawn without consequences.

A bid bond is a small document with a large promise behind it. Treat the bid it backs as a contract you’re ready to sign.