Performance Bond

A financial guarantee, typically issued by a bank or insurer, protecting a contracting authority against contractor default. Usually set at 10% of contract value and called upon if the contractor fails to perform.

What It Is

A performance bond is a surety instrument issued by a third-party guarantor — typically a bank or insurance company — on behalf of a contractor. It provides the contracting authority with a financial remedy if the contractor fails to fulfil its contractual obligations. In UK public-sector contracts, the bond is most commonly set at 10% of the total contract value, though this figure varies by risk profile and sector.

How It Works

The guarantor commits to paying the contracting authority up to the bond's face value upon a valid call. There are two principal types:

• On-demand bonds — payable immediately upon written demand, without the authority needing to prove loss. These offer stronger protection but are more expensive for contractors to obtain.
• Conditional bonds — payable only once the authority has demonstrated actual loss arising from contractor default. More common in UK construction contracts.

The bond is typically procured by the contractor at contract award and remains in force until practical completion or an agreed expiry date. Costs are borne by the contractor but are ordinarily priced into the contract.

Legal and Regulatory Context

Performance bonds are not mandated by the Procurement Act 2023 or its predecessor, the Public Contracts Regulations 2015, but are widely required under standard forms such as JCT, NEC4, and PFI/PPP contracts. The Cabinet Office Construction Playbook (2020) advises authorities to consider the proportionality of bond requirements, warning that excessive financial assurance demands can deter SME bidders and inflate tender prices.

When Contracting Authorities Use Them

Bonds are most appropriate where:

• Contract values are high and mid-contract failure would cause significant disruption
• The contractor's financial standing carries residual uncertainty
• Mobilisation costs or bespoke asset build-up create switching risk
• The supply chain is thin and alternative providers are limited

Practical Considerations

Authorities should check that the guarantor holds an acceptable credit rating (typically A- or above from a recognised agency) and that bond wording is reviewed by legal counsel before acceptance. A bond with poorly drafted call conditions can be effectively unenforceable. Authorities should also avoid conflating a performance bond with a parent company guarantee (PCG), which is an unsecured promise from a corporate parent rather than an independent financial instrument.