65 ILCS 5/9-2-104
Except as otherwise provided in Section 9-2-113, the successful bidder for the construction of such an improvement shall be required to enter into bond in a sum equal to one-third of the amount of his bid with sureties to be approved by the president of the board of local improvements. This bond shall be filed with the board of local improvements, or where there is no board of local improvements, with the municipal clerk. When entering into the contract for the construction of an improvement the bond shall provide that the contractor shall well and faithfully perform and execute the work in all respects according to the complete and detailed specifications, and full and complete drawings, profiles, and models therefor, and according to the time and terms and conditions of the contract, and also, that the bidder and contractor shall promptly pay all debts incurred by him in the prosecution of the work, including those for labor, and materials furnished.
Suit may be brought on the bond in case of default, or failure to pay these debts promptly, by and in the name of the municipality for all damages sustained either by the municipality, or by any person interested or for the damages sustained by the municipality and all parties in interest, or by any beneficiary or party interested, in the name of the municipality for the use of the party interested as beneficial plaintiff, to recover for the labor and materials furnished. However, in no case shall costs be adjudged against the municipality in any suit brought by any party in interest wherein the municipality is the nominal, but not the beneficial, plaintiff.
In advertising for bids or proposals for the construction of such an improvement, the board of local improvements shall give notice that such a bond will be required, and all bids or proposals shall contain an offer to furnish such a bond upon the acceptance of such a bid or proposal.
65 ILCS 5/9-2-104