What is an IFB?

How sealed bidding works

Bidders submit sealed prices by the closing deadline, and the agency opens all bids at once — historically in a public bid opening where every bidder's price is read aloud. The award goes to the lowest bid that is responsive (meets the specification and instructions) and responsible (the bidder is judged capable of performing).

There is no room to clarify or improve a bid after opening. A bid that takes exception to the specification, omits a required form, or arrives late is set aside no matter how low the price.

Where you'll see IFBs

IFBs dominate construction and public works, where drawings and specifications define the work precisely and price is the only honest differentiator. They are also common for commodity purchases and defined-scope services at the state, provincial, and municipal level.

In Canadian practice the equivalent instrument is often called an ITT (Invitation to Tender). The mechanics — sealed pricing, lowest compliant bid wins — are the same.

Winning on price without losing your margin

Since price decides the award, estimating discipline is everything: quantify the specification line by line, price subcontractor scopes firmly, and include the cost of bonds, insurance, and site conditions. The winner's curse — winning by underpricing the true cost — is the classic IFB failure mode.

Responsiveness is the other half. Walk the bid form requirements like a checklist, because IFB disqualifications are overwhelmingly clerical: a missing acknowledgement of an addendum, an unsigned form, or a bid bond in the wrong amount.

Frequently asked questions

What does "responsive and responsible" mean?

Responsive means the bid conforms to the solicitation — specification, forms, and deadline. Responsible means the bidder has the capacity, resources, and record to perform. A bid must be both to win, however low the price.

Can the agency negotiate after bids are opened?

No. Sealed bidding prohibits post-opening negotiation. If all bids come in over budget, the agency's options are to award as-is, cancel, or re-solicit — not to haggle.

Do IFBs require bid bonds?

Construction IFBs usually do — commonly 5-10% of the bid price — along with performance and payment bonds from the winner. Goods and services IFBs often don't. The solicitation states the exact requirement.