Contractors often treat a bid bond as a small formality and the performance bond as the real one. They are the same underwriting decision, made once. Knowing why changes how you plan a bid.

What the bid bond actually promises

A bid bond guarantees two things to the project owner:

  • That if you are awarded the job, you will sign the contract at the price you bid
  • That you will then furnish the required performance and payment bonds

That second promise is the link. The bid bond is not just a pledge to honor your number — it is a pledge to produce a much larger bond later.

Why the surety underwrites both up front

Because the bid bond commits the surety to the performance bond, they cannot approve one without approving the other. When you request a bid bond on a $4,000,000 job, the surety is deciding whether it is prepared to back a $4,000,000 performance bond, and it makes that call before issuing the bid bond.

Which is why a bid bond request triggers the full file: financial statements, work-in-progress schedule, bank line, and your single-job and aggregate limits. A contractor who has never been bonded should not expect to get a bid bond the afternoon before the bid is due.

The dollar amounts are very different

  • Bid bond — usually 5% to 10% of the bid amount, sometimes 20% on public work. Usually issued at no separate charge, since the surety expects to earn the premium on the performance bond.
  • Performance bond — 100% of the contract price in most cases, guaranteeing you complete the work per the contract.
  • Payment bond — usually issued alongside the performance bond, also commonly 100%, guaranteeing your subcontractors and suppliers get paid.

What happens if you back out

Say you bid $2,000,000 with a 10% bid bond and then discover you underbid and walk away. The owner moves to the next bidder at $2,180,000. The owner claims your bid bond for the $180,000 difference, up to the $200,000 penal sum. And because a surety bond is not insurance, you sign an indemnity agreement — the surety pays the owner and then collects from you.

Bonding capacity is a budget

Every bonded contractor has a single-job limit and an aggregate limit across all open work. Bid bonds consume capacity the moment they are issued, because the surety has to reserve room for the performance bond that may follow. Bid four jobs at once and you may find the fourth declined — not because you are a bad risk, but because you have committed your program.

Where the requirement comes from

On federal construction contracts above a set threshold, the Miller Act requires performance and payment bonds. Most states have their own version, often called a Little Miller Act, covering state and municipal work. Private owners and general contractors frequently require the same package by contract.

What to tell a contractor before bid day

Start the bonding file before you need it, not the week of the bid. Get the surety comfortable with your financials and your work on hand, and know your single-job and aggregate limits before you decide which jobs to chase. The bid bond is the easy part — the surety already decided the hard part when they issued it.

Related: Bid bonds and performance bonds — the basics · What is a surety bond?

Educational only — confirm against the actual bond form, the bid documents, and the surety's requirements.