Bid bonds play an important role in California public construction by protecting public agencies when a successful bidder refuses or fails to enter into the contract after award. Public entities often require contractors to submit bid security with their proposals, commonly in the form of a bid bond issued by an admitted surety insurer. If the bidder is awarded the project but does not execute the contract, provide required performance and payment bonds, or satisfy other post-award requirements, the agency may seek to forfeit the bid security or make a claim against the surety.
Bid bond liability is not automatic, however. Disputes may arise over whether the public agency made a valid award, whether the bidder was entitled to relief because of a clerical mistake, whether the agency complied with the solicitation, whether the contract presented for execution materially differed from the bid documents, whether the bid remained open when the award occurred, and what damages or forfeiture the bond actually covers. California’s Public Contract Code also provides a specific statutory framework for bidders seeking relief from qualifying mistakes, making timing and documentation particularly important.
What Is a Public Works Bid Bond?
A bid bond is a form of security submitted with a contractor’s bid on a public project. The contractor is the principal, the public entity is generally the obligee, and the bonding company acts as the surety.
The bond typically guarantees that if the contractor is selected for the project, the contractor will satisfy specified post-award obligations such as:
- Executing the construction contract;
- Providing required performance bonds;
- Providing required payment bonds;
- Submitting required insurance documentation;
- Meeting other conditions stated in the notice of award or bidding documents; and
- Proceeding with the contract according to the terms of the bid.
If the successful bidder refuses or fails to satisfy those obligations, the public agency may attempt to enforce the bid security.
Bid Security Is Different From Performance and Payment Bonds
Bid bonds should not be confused with the bonds required after the construction contract is awarded.
A bid bond protects the public agency during the bidding and contract-award process. Its principal purpose is to provide security against a successful bidder’s failure to follow through on its bid.
A performance bond, by contrast, generally protects the public entity against contractor default during performance of the construction contract. A payment bond protects qualifying subcontractors, suppliers, laborers, and other claimants against nonpayment in accordance with applicable law and the bond.
The timing is therefore different:
- Bid security generally applies before the construction contract is fully executed;
- A performance bond generally applies after contract formation and during performance; and
- A payment bond generally protects specified payment obligations associated with the work.
Identifying which bond is involved is essential because different legal rights, defenses, and procedures may apply.
California Public Agencies Use Different Bid Security Requirements
There is no single bid bond amount that applies identically to every California public works solicitation. Applicable statutes, agency rules, and bidding documents may determine what form and amount of security must accompany a bid.
Depending on the project, acceptable security may include:
- A bid bond issued by an admitted surety insurer;
- Cash;
- A cashier’s check;
- A certified check; or
- Another form specifically authorized by the applicable procurement requirements.
Many public construction solicitations require bid security calculated as a percentage of the bid amount, but contractors should review the particular invitation for bids rather than assume that a percentage used on another public project applies.
The Bond Language and Bid Documents Should Be Read Together
A bid bond claim generally cannot be evaluated by looking at the bond alone. The bond is commonly tied to obligations contained in the invitation for bids, instructions to bidders, notice inviting bids, proposal forms, and other procurement documents.
Relevant documents may include:
- The bid bond;
- The contractor’s proposal;
- Instructions to bidders;
- The notice inviting bids;
- Addenda;
- The proposed construction agreement;
- Performance and payment bond forms;
- Insurance requirements;
- The notice of award;
- Bid validity provisions; and
- Correspondence between the agency and bidder.
The central issue is often whether the event triggering the bond actually occurred under the terms governing the procurement.
When Can a Public Agency Assert a Bid Bond Claim?
A common bid bond claim arises when the successful bidder refuses or fails to execute the contract after a proper award.
Other potential triggering events may include failure to provide required bonds or insurance if those obligations are expressly part of the bidder’s secured commitment.
A public entity considering a claim should determine:
- Whether a valid award was made;
- Whether the contractor received proper notice of award;
- What documents the contractor was required to provide;
- What deadline applied;
- Whether the bidder actually refused or failed to comply;
- Whether a statutory basis for bid relief exists;
- Whether the agency complied with its own bid procedures; and
- What remedy is authorized by the bid bond and applicable law.
Failure to Execute the Contract Is a Typical Trigger
Public bid documents frequently provide that the bidder’s security may be forfeited when the successful bidder fails or refuses to execute the construction agreement within the period required after award.
Before pursuing forfeiture, however, the agency should confirm that the contract presented for execution corresponds with the agreement contemplated by the bidding documents.
If the agency materially changes the bidder’s obligations after bid opening, the bidder or surety may argue that the contractor was not required to execute a materially different agreement.
The significance of any change depends on the bidding documents, bond language, applicable procurement law, and the nature of the modification.
Failure to Provide Performance or Payment Bonds Can Also Create Exposure
Public works solicitations commonly require the successful contractor to provide performance and payment bonds as a condition of contract execution.
If a contractor submits a bid supported by a bid bond but later cannot obtain the required project bonds, the public agency may contend that the contractor failed to satisfy its secured post-award obligations.
This risk makes contractor bonding capacity important before bid submission.
A contractor should confirm in advance:
- Required performance bond limits;
- Required payment bond limits;
- Surety qualifications;
- Bond forms required by the agency;
- Whether special endorsements are required;
- Whether the surety has approved the contemplated project; and
- Whether the contractor’s aggregate bonding capacity can support the award.
A Bidder’s Inability to Obtain Final Bonds Is Not Necessarily a Defense
A contractor may discover after bid opening that its surety will not issue the performance or payment bonds required for the project. That circumstance does not necessarily excuse the bidder from the obligations secured by the bid bond.
The agency may argue that evaluating bonding capacity before submitting the bid was the contractor’s responsibility.
Possible defenses should therefore be based on the contract, bond, statutory rights, and facts rather than an assumption that post-bid financing or bonding problems automatically permit withdrawal.
California Provides Statutory Relief for Certain Bid Mistakes
California Public Contract Code Sections 5100 through 5110 establish a statutory framework for relief from certain mistakes made in bids submitted through competitive bidding for public construction.
The statutes apply to bids submitted to covered public entities for construction, alteration, repair, or improvement projects.
This procedure is particularly important because a successful bidder that discovers a genuine clerical error after bids are opened may otherwise face a difficult choice between performing an economically damaging contract and risking forfeiture of its bid security.
Four Requirements Generally Apply to Bid Mistake Relief
Under Public Contract Code Section 5103, a bidder seeking statutory relief must establish several elements.
The bidder must generally establish that:
- A mistake was made;
- The bidder provided written notice to the public entity within five working days after bid opening, excluding Saturdays, Sundays, and state holidays;
- The notice specified in detail how the mistake occurred;
- The mistake made the bid materially different from what the bidder intended; and
- The mistake occurred in filling out the bid rather than resulting from an error in judgment, carelessness in inspecting the site, or carelessness in reading the plans or specifications.
These distinctions can determine whether the bidder receives relief without losing its security.
Clerical Mistakes and Errors in Judgment Are Treated Differently
California’s bidder-relief statute does not provide a general opportunity to reconsider a bid after competitors’ prices become public.
A mathematical or clerical input error may potentially qualify if the statutory requirements are satisfied. By contrast, a contractor may have greater difficulty obtaining statutory relief when the claimed problem results from poor estimating judgment or a failure to understand the plans.
Potential qualifying mistakes may include circumstances such as:
- A misplaced decimal;
- A transposed number;
- An incorrect quantity entered into a spreadsheet;
- An arithmetic calculation error;
- An omitted component caused by a clerical entry mistake; or
- Another demonstrable error in preparing the bid form.
By contrast, disputes involving underestimated productivity, intentionally selected unit prices, misunderstood site conditions, or failure to properly review specifications may present significantly different issues.
Bid Worksheets Can Become Critical Evidence
A contractor seeking relief should be prepared to show exactly how the alleged mistake occurred.
Contemporaneous estimating documents may include:
- Bid worksheets;
- Estimating spreadsheets;
- Quantity takeoffs;
- Supplier quotations;
- Subcontractor quotations;
- Estimator notes;
- Internal bid review documents;
- Email communications;
- Bid recap sheets; and
- Electronic calculation histories.
These records may demonstrate both the intended amount and the specific clerical error that caused the submitted bid to differ.
Contractors should preserve these materials immediately after discovering a mistake rather than recreating calculations later.
The Five-Working-Day Notice Requirement Is Important
Section 5103 requires written notice of the claimed mistake within five working days after bid opening, excluding Saturdays, Sundays, and state holidays.
The notice should not merely state that the contractor made an error. It should explain in detail how the mistake occurred.
A useful notice may identify:
- The bid item affected;
- The incorrect entry;
- The intended entry;
- The calculation involved;
- The resulting difference in price;
- Supporting worksheets; and
- Why the error is clerical rather than an error of judgment.
Because the statutory window is short, a contractor that discovers a potential bid mistake should review it immediately.
The Public Entity May Consent to Bid Relief
California law permits an awarding authority to consent to relief from a mistaken bid when the statutory requirements are satisfied.
For state awarding authorities, Section 5101 contains documentation requirements when relief is granted, including preparation of a written report establishing the facts supporting the statutory elements.
Public entities commonly evaluate:
- The timing of the bidder’s notice;
- The contractor’s explanation;
- Supporting estimating records;
- The size and materiality of the mistake;
- Whether the mistake was genuinely clerical; and
- Whether granting relief is consistent with competitive bidding requirements.
A Public Agency’s Refusal to Grant Relief Does Not Always End the Matter
Public Contract Code Section 5101 provides a mechanism through which a bidder may seek recovery of forfeited bid security if the awarding authority does not consent to relief.
The litigation procedure is subject to strict requirements. Under Section 5102, the complaint must be filed and the required summons served within 90 days after bid opening or the action is subject to dismissal.
A contractor considering judicial relief should therefore act promptly rather than waiting until an extended negotiation with the public agency concludes.
The bidder ultimately must establish the statutory elements supporting relief.
The Bidder May Face Litigation Costs if Relief Is Denied
Section 5101 also creates potential consequences for a bidder that unsuccessfully pursues court recovery of forfeited security.
If the bidder fails to obtain judgment, the statute provides for payment of the public entity’s costs, including a reasonable attorney’s fee fixed by the court.
This makes early evaluation of the evidence particularly important. A contractor should determine whether its estimating records actually demonstrate a qualifying statutory mistake before pursuing litigation.
A Bidder Claiming Mistake Cannot Continue Bidding on the Same Project
Public Contract Code Section 5105 provides an important consequence that contractors sometimes overlook.
A bidder that claims a mistake or forfeits its bid security is prohibited from participating in further bidding on the project on which the mistake was claimed or security forfeited.
This protects competitive integrity by preventing a bidder from withdrawing after seeing competitors’ prices and then simply submitting a revised bid on the same project.
Whether a later solicitation constitutes the same project can become fact-specific when an agency rejects all bids, changes the work, and later readvertises it.
The Public Agency May Proceed to Another Bidder
Public Contract Code Section 5106 permits a public entity, if it determines that doing so is in its best interest, to award the contract to the second-lowest bidder when the successful bidder refuses or fails to execute the contract.
If the second-lowest bidder likewise refuses or fails to execute after receiving the award, the agency may proceed to the third-lowest bidder.
The statute also addresses forfeiture of bidder security when the second or third bidder receives the award and then refuses or fails to execute the contract.
Whether the agency may award to another bidder in a particular procurement may also depend on the laws and bid requirements governing the awarding entity.
A Mistake in a Subcontractor’s Quote Is Not Automatically a Mistake in the Prime Bid
Prime contractors frequently rely on last-minute subcontractor quotations when preparing public works bids. A subcontractor may contact the prime contractor after opening and claim that its quotation contained a substantial mistake.
That does not necessarily mean the prime contractor itself satisfies California’s statutory bidder-relief requirements.
California appellate authority has distinguished a mistake made by the general contractor in filling out its own public bid from a mistake contained in a subcontractor’s proposal that the general contractor intentionally incorporated into its bid.
The prime contractor may have separate legal issues involving reliance on the subcontractor’s quotation, promissory estoppel, subcontract formation, or substitution, but those issues should not automatically be treated as a qualifying Section 5103 mistake.
Bid Responsiveness and Bid Mistake Are Different Issues
A bidder may also face a dispute because the public agency considers its proposal nonresponsive.
Responsiveness generally concerns whether the bid materially complies with the solicitation requirements.
Potential problems may involve:
- Missing signatures;
- Failure to acknowledge an addendum;
- Missing bid security;
- Improper bond forms;
- Material qualifications or exceptions;
- Incomplete subcontractor information;
- Missing required certifications;
- Conditional pricing; or
- Failure to submit mandatory bid documents.
A nonresponsive bid issue is not necessarily the same as a bidder seeking relief because it accidentally entered an incorrect price.
Not Every Bid Irregularity Permits Withdrawal Without Consequences
A bidder may argue that because its bid contains a defect, the bid could not have been accepted and therefore its bid bond should not be exposed.
That argument depends on the nature of the defect.
Some irregularities may be immaterial and waivable by the public agency, while others may make the proposal materially nonresponsive.
Courts generally examine whether the irregularity affects competitive bidding principles, gives one bidder an unfair advantage, or permits the bidder to decide after bid opening whether to accept or reject the contract.
The existence of a technical error should therefore not automatically be treated as an unrestricted right to withdraw.
A Valid Award Can Be an Important Element of a Bid Bond Claim
A surety defending a bid bond claim may examine whether the public agency actually awarded the contract to the principal in accordance with applicable law and the bidding documents.
Potential issues can include:
- Whether the principal was the selected bidder;
- Whether the award was made by the authorized public body;
- Whether required approvals occurred;
- Whether the award occurred while the bid remained valid;
- Whether material conditions were added after opening;
- Whether the agency rejected the bid before attempting to enforce it; and
- Whether the underlying procurement complied with mandatory competitive bidding procedures.
A bid bond generally secures the bidder’s obligation arising from the bid and award process. If no enforceable obligation arose, the surety may dispute liability.
Bid Validity Periods Can Become Important
Public solicitations frequently require bids to remain open for a specified period after opening.
The agency may make an award during that period or request an extension if additional time is necessary.
A dispute may arise when the agency attempts to make an award after the stated bid validity period has expired without obtaining the bidder’s agreement to extend its proposal.
Relevant documents may include:
- The invitation for bids;
- Bid proposal language;
- Addenda;
- Extension requests;
- Contractor responses; and
- The date of formal award.
The effect of expiration depends on the procurement requirements and specific communications between the parties.
A Materially Different Contract Can Create a Defense
A bid bond typically guarantees that the successful bidder will enter into the contract contemplated by the bid documents. It does not necessarily authorize the public entity to fundamentally rewrite the bargain after bids are opened.
A bidder or surety may challenge liability when the agency attempts to require materially different:
- Scope of work;
- Contract price;
- Bonding requirements;
- Insurance requirements;
- Completion obligations;
- Risk allocation; or
- Other material contract terms.
Minor administrative changes are different from substantial modifications that alter the bidder’s obligation.
The significance of a change must be evaluated in the context of the original solicitation.
The Surety’s Liability Is Generally Tied to the Principal’s Obligation
California suretyship principles generally provide that a surety’s obligation cannot be more burdensome than the principal obligation it secures.
This means that defenses available to the bidder may also affect the surety’s liability.
For example, the surety may investigate whether:
- The bidder was legally excused;
- The public entity granted statutory bid relief;
- No valid award occurred;
- The bid had expired;
- The agency materially changed the contemplated contract;
- The claimed event falls outside the bond conditions; or
- The amount sought exceeds the bond’s applicable limit.
The surety may also possess defenses arising directly from the bond language.
The Penal Sum of the Bond Can Limit Exposure
A bid bond usually states a maximum amount for which the surety can be liable.
The public agency should therefore identify:
- The penal sum;
- How it was calculated;
- Whether the required bid security was properly submitted;
- Whether the agency seeks forfeiture or compensatory damages; and
- Whether the amount sought is authorized under the applicable bond and procurement documents.
A public entity generally should not assume that every project-related loss can be shifted to the bid bond simply because the contractor failed to proceed.
Forfeiture and Actual Damages Should Be Distinguished
Some bid documents characterize the bidder’s security as subject to forfeiture if the successful bidder fails to execute the contract. Other bond language may tie liability to damages resulting from the bidder’s failure.
This distinction can matter if the agency ultimately awards the project to another contractor at a higher price.
Potential claimed losses may include:
- The increased contract price;
- Costs associated with rebidding;
- Administrative expenses;
- Delay-related costs; and
- Other amounts allegedly resulting from the failed award.
The recoverability of any category depends on the governing statute, bid documents, bond language, and applicable contract and surety principles.
The Difference Between the First and Second Bid Can Become Important
If the low bidder refuses to execute and the public entity awards the work to the next bidder at a higher price, the price difference may become part of the agency’s claimed loss.
However, the calculation may require close review.
Questions may include:
- Whether the scope remained identical;
- Whether alternates changed;
- Whether unit quantities changed;
- Whether the agency delayed the award;
- Whether the second bidder’s proposal remained valid;
- Whether rebidding would have reduced the loss; and
- Whether the claim is limited by the penal sum of the bond.
Public Entities Should Preserve the Procurement Record
A public entity pursuing a bond claim should preserve a complete record of the procurement.
Important documents may include:
- The solicitation;
- Bid advertisements;
- Addenda;
- All bids received;
- The bidder’s security;
- Bid opening records;
- Staff evaluations;
- Bid relief requests;
- Board or council agenda materials;
- Award resolutions;
- Notice of award;
- Contract execution communications;
- Surety correspondence; and
- Evidence of any resulting financial loss.
A well-documented procurement record can help establish both liability and damages.
Contractors Should Preserve Their Estimating File
For bidders, the estimating file may be the most important evidence in a mistake-relief dispute.
Companies should preserve:
- Original spreadsheet versions;
- Takeoff software data;
- Bid-day notes;
- Supplier proposals;
- Subcontractor quotes;
- Estimator communications;
- Internal approval records;
- Calculation sheets;
- Electronic timestamps; and
- Documents showing the intended bid.
Destroying or overwriting these materials can make it substantially more difficult to prove that a claimed error was truly clerical.
Bid Protests and Bid Bond Claims Can Overlap
A competing bidder may challenge an award while the selected bidder simultaneously disputes its own obligation to proceed.
For example, one bidder may contend that the apparent low bid is nonresponsive while the low bidder seeks withdrawal because of a mistake.
These disputes can affect:
- Whether a valid award occurs;
- Which bidder is next in line;
- Whether bid security may be forfeited;
- Whether the agency should reject all bids;
- Whether the project should be rebid; and
- Whether judicial relief is necessary.
Public entities should address each issue separately rather than assuming that one dispute automatically resolves the others.
Sureties Should Investigate Before Paying a Bid Bond Demand
A surety receiving a demand should promptly obtain the underlying procurement documents and communicate with its principal.
A reasonable investigation may examine:
- The bond;
- The contractor’s bid;
- The award;
- The alleged default;
- The contract presented for execution;
- The contractor’s explanation;
- Any mistake-relief request;
- The agency’s response;
- Whether another bidder received the contract; and
- The agency’s damages calculation.
The surety should also determine whether statutory deadlines or pending litigation may affect its rights.
Contractor and Surety Interests May Not Always Be Identical
A contractor may want to preserve its relationship with the public entity while the surety focuses on whether the claim falls within the bond.
The surety may also have reimbursement and indemnity rights against the contractor under agreements executed when the bonding relationship was established.
If the surety pays the agency, the contractor and its indemnitors may ultimately face a demand to reimburse the surety for amounts paid and certain associated expenses, depending on the governing indemnity agreement.
Contractors should therefore treat a bid bond claim as a potentially significant financial matter rather than assuming the surety alone bears the loss.
General Indemnity Agreements Can Create Separate Exposure
Sureties commonly require contractors and sometimes related companies or individuals to execute general agreements of indemnity as a condition of providing bonding.
Those agreements may provide the surety with rights involving:
- Reimbursement for bond payments;
- Recovery of investigation or legal expenses;
- Collateral security;
- Access to contractor records;
- Settlement authority; and
- Other protections associated with bond claims.
The surety’s rights against its indemnitors are separate from the public entity’s rights under the bid bond and can generate additional litigation after the public claim is resolved.
Early Communication Can Sometimes Avoid Bid Bond Litigation
When a contractor discovers a genuine mistake immediately after bid opening, rapid communication can be critical.
A contractor should consider promptly:
- Freezing and preserving its estimating records;
- Calculating the precise effect of the mistake;
- Preparing the statutory written notice;
- Providing supporting documents;
- Notifying the surety;
- Reviewing the bid documents;
- Evaluating the Section 5103 requirements; and
- Tracking all statutory litigation deadlines.
A public agency receiving a well-documented request can then evaluate whether voluntary relief is appropriate before the dispute develops into a bond claim.
Contractors Can Reduce Bid Bond Risk Before Submission
Bid bond disputes often arise because of problems that could have been identified during bid preparation.
Risk-management procedures may include:
- Using a formal bid review checklist;
- Having a second estimator review major calculations;
- Confirming all addenda;
- Verifying unit-price extensions;
- Checking subcontractor quotes for obvious discrepancies;
- Confirming bonding capacity;
- Reviewing insurance requirements;
- Confirming bid security requirements;
- Checking bid validity periods;
- Preserving final estimating worksheets; and
- Reviewing the proposed contract before bid submission.
These procedures can reduce both the likelihood of error and the difficulty of proving what occurred if a mistake is later discovered.
Did You Know?
Under California Public Contract Code Section 5105, a bidder that claims a qualifying mistake or forfeits its bid security is prohibited from participating in further bidding on the project for which the mistake was claimed or the security forfeited.
Protecting Rights in California Public Works Bid Bond Disputes
Public works bid bond claims can involve competitive bidding rules, bid responsiveness, statutory mistake relief, forfeiture, surety defenses, contract execution requirements, bonding capacity, and disputes over the amount recoverable by the public agency. Because California provides short deadlines for certain bidder-relief procedures, contractors, public entities, and sureties should evaluate these disputes promptly and preserve the complete bidding record.
Putterman Law represents contractors, subcontractors, owners, public works participants, and other construction businesses in disputes involving public bidding, bond claims, contract awards, public works obligations, and related construction litigation.
Learn more about construction law services at Putterman Law
FAQs
What does a public works bid bond guarantee?
A bid bond generally secures the successful bidder’s obligation to proceed with the award according to the bid documents, commonly including execution of the construction contract and provision of required performance and payment bonds. The exact obligation depends on the bond and procurement documents.
Can a California public works contractor withdraw a bid after discovering a mistake?
Potentially. California Public Contract Code Sections 5100 through 5110 provide relief for certain qualifying bid mistakes. The bidder generally must establish a genuine mistake, timely written notice, a material difference from the intended bid, and an error in filling out the bid rather than an error of judgment or failure to properly review the site, plans, or specifications.
How quickly must a contractor report a bid mistake in California?
Public Contract Code Section 5103 generally requires written notice to the public entity within five working days after bid opening, excluding Saturdays, Sundays, and state holidays. The notice must explain in detail how the mistake occurred.
Can a contractor obtain bid relief because a subcontractor made a pricing mistake?
Not automatically. California appellate authority distinguishes a mistake made by the prime contractor in filling out its public bid from a mistake contained in a subcontractor’s quotation that the prime intentionally used. Separate contract or promissory estoppel issues may arise between the prime contractor and subcontractor.
What happens if the public agency refuses to excuse a mistaken bid?
A bidder may have a statutory action to recover forfeited security if it can establish the requirements for relief. Public Contract Code Section 5102 imposes a strict 90-day period after bid opening for filing the complaint and completing the required service, so prompt legal review is important.
Can a bidder that withdraws because of a mistake rebid the same project?
Public Contract Code Section 5105 generally prohibits a bidder that claims a mistake or forfeits its bid security from participating in further bidding on the project involved. Whether a substantially revised and later advertised project is considered the same project can depend on the circumstances.
Can a surety defend a bid bond claim when the contractor had a valid defense?
Potentially. Surety liability is generally tied to the obligation secured by the bond. Issues such as statutory bid relief, lack of a valid award, expiration of the bid, material changes to the contemplated contract, or failure to satisfy bond conditions may affect both principal and surety liability.
Is the surety always responsible for every cost the public agency incurs after a bidder defaults?
No. The surety’s exposure depends on the bid bond, its penal sum, the procurement documents, applicable law, and the nature of the agency’s claimed damages or forfeiture. The amount sought should be evaluated against the specific obligation the bond secures.
