Collateral warranties and performance bonds are now a common part of construction procurement and a standard feature in contract negotiations across the supply chain. Whether you are a main contractor, subcontractor, or a supplier, there is a real chance you will be asked to provide one or both as a condition of award. Likewise, you may be expected to procure these from your own supply chain. Despite how routine they have become, these documents carry real commercial consequences that can expose your business to significant risk if misunderstood or agreed too hastily. In this article, we explain their core functions, the risks that come with them, and the steps you can take to protect your position.
Collateral warranties
A collateral warranty is a separate legal agreement that creates a direct contractual relationship between a contractor or subcontractor and a third party, typically someone with an interest in the project such as a funder, tenant, purchaser, or end-user. In the absence of such a warranty, these third parties would ordinarily have no right to bring a claim for defective work or delay. That’s because they are not a party to the underlying construction contract – a principle known in English law as privity of contract. Put simply, you cannot enforce or be bound by a contract you are not part of. This creates a clear boundary around who can sue whom, which is where collateral warranties come in.
They bridge that gap by extending the contractor’s or subcontractor’s duty of care to the third party. While this might appear to be a sensible commercial solution, in practice it opens the warrantor up to a separate and potentially long-lasting line of liability, often to the parties with whom they have had no direct dealings, and who may be more inclined to pursue claims due to their financial interest in the finished project rather than the construction process itself.
Collateral warranties often include broad obligations such as a duty to carry out works with reasonable skill and care and frequently last six, twelve, or even more years, particularly if executed as a deed. Risks arise when the terms of the warranty expand or modify the scope of liability beyond that set out in the main contract.
Clauses imposing fitness for purpose obligations, indemnities, or unlimited liability are not uncommon and should be treated with caution. Similarly, terms allowing multiple assignments of the warranty can significantly increase the warrantor’s exposure and so too warrant close scrutiny. Contractors and subcontractors should not assume the warranty is standard or harmless. A thorough review is always required to ensure it mirrors the terms of the original contract and does not extend liability in ways that are commercially unreasonable or uninsured.
Performance bonds
Performance bonds are financial instruments used to provide security to an employer in the event that a contractor fails to perform its obligations. Typically, it is arranged through a bank or a specialist insurer with expertise in surety and construction risk, these bonds are usually set at 10% of the contract value and are triggered upon a contractor’s default, most commonly that is non-performance or insolvency.
There are two key types of performance bonds, and understanding the distinction is essential. The first is an on-demand bond, which allows the beneficiary to demand payment without having to prove a breach or quantify any loss. These bonds pose a significantly higher risk to contractors and are rarely appropriate in UK domestic projects and thus less commonly used. In contrast, the second, and more typical, is a conditional bond (also known as a guarantee bond) which requires evidence of both breach and resulting loss before payment can be triggered. This is the industry norm and offers more balanced protection. Contractors should be clear about which type of bond is being proposed and ensure it aligns with the project’s risk profile.
Although often requested as part of a routine procurement process, performance bonds should be approached cautiously. The wording of the bond is crucial. It must be tightly drafted to ensure the bond provider’s liability is clearly defined and limited to genuine, demonstrable breaches of the contract. Vague triggers or poorly defined obligations can result in claims being made in circumstances that were not originally intended.
It is important that contractors understand the cost implications of the bonds. They do carry an annual premium which should be factored into tendered rates. Furthermore, the bond should never apply to liabilities that extend beyond the scope of the construction contract itself.
Commercial impact
Warranties and bonds are often demanded as standard conditions of appointment, but their implications should not be underestimated. For subcontractors, the requirement to provide warranties to third parties, such as funders or purchasers, can substantially increase legal exposure without any corresponding increase in payment.
In some cases, a contractor may be asked to provide both a performance bond and a parent company guarantee, leading to unnecessary duplication of security and what is often referred to as over-securitisation. This can impact a contractor’s credit position and insurance coverage.
Where the documents include onerous clauses, such as unlimited liability, obligations to comply with strict specifications, or assignment without consent, parties may find themselves facing risks that are disproportionate to the contract value and of a scale that cannot reasonably be justified on commercial grounds.
Bonding capacity – a commercial constraint
It is worth remembering that performance bonds are typically underwritten against a contractor’s overall bonding capacity. This is not unlimited. Many contractors have to manage their bonding availability carefully across multiple projects. Agreeing to provide a bond for lower value works can unnecessarily tie up capacity that may be needed for larger or more strategic projects. This is a relevant commercial consideration when deciding whether to offer a bond and should be factored into your wider procurement strategy.
Practical considerations
If you are presented with a collateral warranty or performance bond, review it line by line. Do not assume the form is non-negotiable. Watch out for clauses that increase your liability or introduce new obligations. Make sure that the terms of any warranty reflect those in your main contract.
If your underlying obligation is to exercise reasonable skill and care, a warranty imposing a fitness for purpose standard would be inconsistent and likely uninsurable. Where possible, negotiate limits on liability, such as a cap tied to the contract value and resist clauses that allow for unlimited or open-ended assignment.
If you are a main contractor passing risk down the supply chain, make sure you are not left carrying exposure that has not been mirrored in your subcontracts. And most importantly, involve legal or commercial advisers at the outset, when you still have leverage to influence the terms.
How CCC can help
At Contract & Construction Consultants (CCC), we support clients across the supply chain to manage warranty and bond obligations with confidence. We can:
- Review and negotiate warranty and bond terms before you commit
- Help you assess and mitigate risks tied to these documents
- Support you in back-to-back arrangements across your supply chain
- Represent you in disputes involving warranty claims or bond enforcement
If you are being asked to sign a collateral warranty or provide a bond and you are unsure of the implications, get in touch. We can help you protect your position before the paperwork becomes a problem.
