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Estimating & Biddingaka: ITBaka: advertisement for bidsaka: IFB

Invitation to Bid

In Plain English

The official notice from an owner asking contractors to submit their prices for a project.

Definition

An invitation to bid (ITB) is a formal document issued by an owner inviting qualified contractors to submit competitive bids for a defined construction project. It specifies the project description, bid due date, location, bonding requirements, and instructions for obtaining bid documents. Public agencies are often required by law to publicly advertise invitations to bid.

Why It Matters in Bidding

The ITB is the trigger that launches the entire estimating effort, defining the bid window, required documents, bonding and prequalification thresholds, and submission rules that determine whether a bid is even responsive. Missing a stated requirement in the ITB, such as a bid bond amount or a mandatory pre-bid meeting, can get an otherwise competitive proposal rejected before the numbers are ever reviewed.

Example

An estimator scanning a public agency's invitation to bid notes the mandatory pre-bid walkthrough on the 10th, the 5 percent bid bond, and a four-week window, then schedules takeoff and sub solicitation to land quotes two days before the bid deadline.

Related Terms

Bid DocumentsBid DayBid OpeningCompetitive Bidding

Frequently Asked Questions

An ITB seeks a price on a fully defined scope and typically awards to the lowest responsive, responsible bidder. An RFP solicits qualifications, methodology, and price together and lets the owner weigh value beyond cost. ITBs dominate public hard-bid work; RFPs are common where approach and experience matter as much as price.
Public agencies typically post them on their procurement portals, in local newspapers of record, and on state or regional bid boards and plan rooms. Many also notify prequalified contractor lists directly. Estimators monitor these sources and aggregator services to catch ITBs early enough to assemble sub coverage before the deadline.
Yes. The ITB sets responsiveness rules, and failing to meet them, such as omitting a required bid bond, skipping a mandatory pre-bid meeting, missing the deadline, or not holding required licenses or prequalification, can render a bid nonresponsive. Owners must reject nonresponsive bids regardless of price on most public projects.

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