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Agency Alert

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Federal law requires that IDOT maintain a list of all contractors and subcontractors performing work on department projects. Subcontractors will be required to register with the department before being approved to work on projects. Prequalified contractors are automatically included in the list and are NOT required to register. Material suppliers, trucking companies, and companies providing professional services (consultants) are NOT included in this definition of subcontractor and are not required to register.

Updated every Monday, the List of Registered Subcontractors (Text File), provides their registration number, name, address, phone, fax numbers.

This section of the website is designed to outline the role and responsibilities of subcontractors as it relates to IDOT projects. Subcontractor information can be found below, please click each item to expand.

Partnering with Primes

The Transportation Bulletin details the projects being advertised. Subcontractors must deal directly with the prime contractors that are authorized to bid on a project. There are two ways to communicate with the prime contractor to express interest.

  1. The For Bid List of Bidders can be used to contact authorized prime contractors to offer a quote for their portion of the work.

    Note: The first version of this list is posted two weeks following the posting of the Notice of Letting Bulletin. It is then updated each Friday and on the day before the letting.

  2. The Industry Marketplace can be used to provide quotes on certain jobs at the request of prime contractors.

Subcontractor Registration

Per federal law all subcontractors are required to register with IDOT in order to be eligible to work for a prime contractor on state let projects.

Getting Started

Subcontractors can register online via the Subcontract Registration Form. The registration form requires minimal information and can be completed in minutes. Confirmation, along with a 5 digit registration number, will be received via email in one to two days. Registration is valid for one year and will require renewal.


Approximately one month prior to expiration, a notice to renew and instructions will be sent via email. If a subcontractor does not have a valid email address, a notice will be sent via postal mail. Subcontractors can renew their registration on line via the Subcontractor Registration Update Form.


If a revision is required at any time, please do not register again. Revisions can be made by submitting a Subcontractor Registration Update Form or by calling a department representative.

Need Help?

Questions or comments may be addressed to IDOT's Prequalification Section, Bureau of Construction at:

(217) 782-3413

Responsibility of the Prime (Subcontractor Documents)

Once a contract is awarded, IDOT interacts with the prime and the prime alone. In order to further clarify roles and increase understanding of the process, the following is provided as information.

  1. Vendor Documents
    P.A. 96-0795 , P.A. 96-0920 and P.A. 97-0895 enacted substantial changes to the provisions of the Illinois Procurement Code ( 30 ILCS 500 ). Among the changes are provisions affecting subcontractors. IDOT requires contractors awarded a contract, as a material condition of the contract, to implement and enforce the contract requirements applicable to subcontractors approved in accordance with article 108.01 of the Standard Specifications for Road and Bridge Construction.

    Before subcontractors can be approved by an IDOT district,prime contractors must submit electronically: (1) Financial Disclosures and (2) Subcontractor Certification for each subcontract with a value of $50,000 or greater to Vendor Documents database.
  2. Selected subcontractor
    Sub contractors must be approved by IDOT before they can begin working on a project. The contractor shall submit a hard copy of the form: Request for Approval of Subcontractor (BC 260) to the appropriate district office for approval.

    If the contractor seeks approval of subcontractors to perform a portion of the work, and approval is granted by the department, the Contractor may be required to provide a copy of the subcontract to the Chief Procurement Officer upon request within 15 calendar days after execution of the subcontract.

A subcontractor cannot be approved or begin work until all the documents have been received and approved. These requirements do not apply to material suppliers, truckers and professional service companies.

Subcontractor Responsibility

It is the responsibility of subcontractors and suppliers on IDOT highway construction projects to collect monies that are owed to them by the prime contractor. IDOT is unable to make payments to anyone other than the prime contractor, so you must protect yourself from nonpayment or collection problems.

Navigate to Lien and Bond Claims for more information.

Subcontractors are required to follow the specs, policies, and manuals to complete the work.

Interested in Bidding as a Prime?

Bids for state work are only accepted by authorized prequalified prime contractors. If you are not a prequalified  prime contractor, but are interested in becoming prequalified, please visit the Prequalification page

Interested in the DBE Program?

IDOT strives to maintain an equitable distribution of work for its many business partners. One way to accomplish this is through the department’s administration of the federally mandated DBE Program. The DBE program is intended to provide contracting opportunities to small businesses owned and controlled by socially and economically disadvantaged individuals. On most projects a DBE percentage goal is required.

To view the directory of DBE firms that are certified please view the IL UCP (updated every month).