6.3 Contract Surety Bonds, the Miller Act, and Tennessee Bonding Rules

On the Tennessee Business and Law exam, candidates frequently encounter questions testing the legal relationship among the parties to a surety bond, the remedies triggered when a contractor defaults on a Bid, Performance, or Payment Bond, and the statutory public works bonding mandates under both the Federal Miller Act and the Tennessee Public Works Bond Statute ("Little Miller Act").

Surety Bonds vs. Insurance Policies: The Three-Party Credit Relationship

Although corporate surety bonds are issued by licensed insurance and fidelity companies, a surety bond is NOT an insurance policy. In law and finance, suretyship is an extension of credit and financial guaranty analogous to a bank co-signing a commercial obligation:

• The Three Parties to Every Surety Bond:
  1. The Principal (the Obligor / Contractor): The primary party who owes the underlying contractual duty (to enter the construction contract at the bid price, perform the work according to plans and specifications, or pay subcontractors and material suppliers).
  2. The Obligee (the Project Owner on a prime contract bond, or the Prime Contractor on a subcontractor bond): The protected party to whom the Principal's promise is owed and for whose benefit the bond is issued.
  3. The Surety (the Bonding Company / Corporate Guarantor): The financial guarantor (for federal and public works, typically a corporate surety listed on U.S. Department of the Treasury Circular 570) that lends its financial backing and promises the Obligee that if the Principal defaults, the Surety will satisfy the obligation up to the bond's stated penal sum.
• The General Agreement of Indemnity (GAI) and 100% Reimbursement Duty: The single most important legal distinction between insurance and suretyship is the right of indemnity. When an insurer pays a covered fire or liability claim, it absorbs the loss from pooled premiums and cannot sue its own Named Insured for reimbursement. Before a surety will issue a single bond, however, it requires the contracting company AND its individual owners (and typically their spouses) to sign a legally binding General Agreement of Indemnity (GAI). Under both common-law suretyship and the GAI, if the surety pays a single dollar on a bond claim, the Principal and all personal indemnitors are legally obligated to reimburse the surety 100% for all claim payouts, completion expenses, engineering/consulting fees, and attorney's fees, backed by the owners' personal assets.

Underwriting Bonding Capacity: The Three C's of Surety

To determine a contractor's single-project bonding limit and aggregate bonding capacity (total bonded plus unbonded Work-in-Progress / WIP backlog), a surety underwriter evaluates the Three C's:

1. Character: Integrity, reputation with owners and architects, litigation history, and track record of paying subcontractors and suppliers promptly.
2. Capacity: Technical skill, field supervision, equipment fleet, and demonstrated experience completing projects of similar scope, geographic location, and dollar size.
3. Capital: Verified financial strength measured by CPA-prepared accrual/percentage-of-completion financial statements, Net Working Capital ($\text{Current Assets} - \text{Current Liabilities}$, net of slow receivables, inventory, and related-party loans), tangible Net Worth, bank lines of credit, and manageable debt-to-equity leverage. Sureties commonly require verified net working capital equal to roughly 5% to 10% of the contractor's total uncompleted WIP backlog.

Core Construction Contract Bonds and Subcontractor Default Insurance

• Bid Bond: Submitted with a bid proposal to guarantee to the Obligee (Owner) that if the contract is awarded to the Principal (Bidder) within the bid acceptance period, the Bidder will (1) execute the formal construction contract at the submitted bid price, and (2) furnish the required Performance Bond, Payment Bond, and insurance certificates within the specified time (typically 10 to 15 days). Standard Bid Bond penal sums are 5% to 10% of the bid amount. If an awarded bidder refuses to sign the contract (absent a valid, excusable clerical/mathematical mistake), the Bid Bond responds in one of two ways depending on the bond form:
  • Difference-in-Price (Damages) Bid Bond (Most Common, e.g., AIA Document A310): The Principal and Surety pay the Owner the actual difference between the defaulting low bid and the next lowest responsible bid accepted by the Owner, capped at the penal sum of the Bid Bond: $\text{Difference Bid Bond Payout} = \min\big(\text{Next Lowest Bid} - \text{Defaulting Low Bid},\; \text{Bid Bond Penal Sum}\big)$ Example: If Contractor A bids $2,000,000 with a 5% ($100,000) difference-in-price bid bond, refuses to sign, and the Owner awards the contract to Contractor B at $2,065,000, the surety/contractor owes $65,000. If Contractor B's bid was $2,180,000 (a $180,000 spread), the surety's liability is capped at the $100,000 penal sum.
  • Forfeiture (Liquidated) Bid Bond: The entire penal sum of the bid bond is forfeited as liquidated damages regardless of the spread to the second bidder.
• Performance Bond: Issued in favor of the Obligee (Owner)—typically with a penal sum equal to 100% of the contract price—guaranteeing that the Principal (Contractor) will faithfully perform and complete the construction contract according to the contract documents. If the contractor defaults and the Owner properly declares a formal Termination for Cause, the Surety typically has four completion options:
  1. Finance the Original Contractor: Advance funds or technical support to keep the original Principal working (with the Owner's consent).
  2. Take Over and Complete: Execute a Takeover Agreement with the Owner and hire a completion contractor directly.
  3. Tender a Replacement Contractor: Solicit completion bids and tender a new qualified contractor to contract directly with the Owner, while the Surety pays the excess cost above the remaining unpaid contract balance.
  4. Pay the Penal Sum / Excess Completion Cost: Pay the Owner the lesser of the excess cost of completion or the remaining bond penal sum.
• Labor and Material Payment Bond: Issued alongside the Performance Bond (typically at 100% of the contract price for a single combined bond premium), guaranteeing that the Principal will pay subcontractors, laborers, and material suppliers who furnish labor or materials to the project. On private jobs, a Payment Bond keeps the Owner's real estate free of mechanics' liens; on public jobs, it substitutes for mechanics' lien rights.
• Maintenance (Warranty) Bond, Supply Bond, Subdivision Bond, and SDI:
  • Maintenance (Warranty) Bond: Guarantees correction of defective workmanship or materials during a post-completion warranty period (commonly 1 year after substantial completion).
  • Supply Bond: Guarantees that a material vendor or equipment fabricator will deliver specified goods per a purchase order.
  • Subdivision / Site Improvement Bond: Guarantees to a city or county that a developer/contractor will complete public infrastructure (streets, curbs, storm drains, utilities).
  • Subcontractor Default Insurance (SDI): A two-party first-party insurance policy (not a surety bond) purchased by large Prime Contractors to indemnify the Prime Contractor against financial loss when an unbonded subcontractor defaults, subject to large deductibles and co-payments.

The Federal Miller Act vs. The Tennessee "Little Miller Act"

Under the legal doctrine of sovereign immunity, mechanics' and materialmen's liens can NEVER attach to federal, state, county, or municipal public property. To protect unpaid subcontractors, laborers, and material suppliers on public construction projects, federal and Tennessee statutes mandate public works payment bonds:

For a Tennessee public contract of $500,000, the 25% statutory minimum is $125,000, not 25% of only the amount above $100,000. Procurement documents may require larger performance and payment bonds. The federal threshold listed here follows the current published FAR 28.102-1; always check the agency solicitation and applicable acquisition rules.

Source check (October 13, 2026): Federal Acquisition Regulation 28.102-1.