FIDIC Performance Security (Sub-Clause 4.2): What It Is and How It Works
The Letter of Acceptance arrives, the champagne gets put back in the fridge, and the first real deadline of the project starts running before a single shovel hits the ground: 28 days to deliver a Performance Security the Employer can hold for the entire length of the contract. Contractors who treat it as paperwork find out the hard way that the bank needs time, the Employer's approved form is non-negotiable, and the instrument they are about to sign will outlive the construction phase itself. Here is what Sub-Clause 4.2 actually requires, and where it is most often confused with something else.
What a Performance Security Actually Secures
A Performance Security is a guarantee the Contractor arranges — usually a demand guarantee issued by a bank, sometimes a surety bond — that the Employer can call on if the Contractor fails to properly perform its obligations under the contract. Unlike a notice of claim, it is not something the Contractor writes; it is an instrument the Contractor's bank issues in the Employer's favour, sitting in the background as a financial backstop for the whole life of the project.
Its purpose is broad by design. Where the Advance Payment Guarantee covers one narrow thing — the mobilisation advance — the Performance Security covers the Contractor's overall performance: finishing the Works, remedying defects, and generally not walking away or defaulting. That breadth is exactly why Employers insist on it before the Contractor ever mobilises.
Key Takeaway: The Performance Security backs the Contractor's overall performance of the whole contract, not one specific payment. It is arranged through a bank or insurer, not written by the Contractor, and it covers the project from before mobilisation until well after practical completion.
The Sub-Clause 4.2 Mechanism: Amount, Deadline, and Form
Under the FIDIC 1999 Red and Yellow Books, and carried through into the 2017 Second Edition, Sub-Clause 4.2 ("Performance Security") sets out three things the Contractor cannot get wrong:
- The amount. Stated in the Appendix to Tender (1999) or the Contract Data (2017), almost always as a percentage of the Accepted Contract Amount. There is no universal FIDIC default percentage — it is whatever the particular contract fixes, and if no amount is stated, the sub-clause simply does not apply.
- The 28-day deadline. The Contractor must deliver the Performance Security to the Employer within 28 days after receiving the Letter of Acceptance, with a copy sent to the Engineer. This is a contract-formation deadline, not a claims deadline — a point worth returning to, because the number 28 shows up twice in FIDIC for very different reasons.
- The approved form. The security must be issued by an entity, and from within a country or jurisdiction, that the Employer approves, and in the form annexed to the contract or another form the Employer agrees to. A Contractor cannot simply hand over whatever its own relationship bank happens to issue as standard.
In practice, the 28 days goes fast. Banks need time to assess the Contractor, issue an instrument in an unfamiliar approved format, and in some jurisdictions route it through a correspondent bank. Treating the Performance Security as a Day 1 task — ideally started during the tender period, once the award looks likely — is what keeps mobilisation on schedule.
Key Takeaway: The amount lives in the Appendix to Tender or Contract Data as a percentage of the Accepted Contract Amount — never assume a standard figure. The 28-day delivery clock starts at the Letter of Acceptance, and the form must already be in the Employer's approved wording.
When the Employer Can Call the Performance Security
A Performance Security is not a blank cheque the Employer can draw on at will. Sub-Clause 4.2 limits a valid call to amounts the Employer is actually entitled to under the Contract, and requires the Employer to first notify the Contractor stating the nature of the default being claimed for. This matters because the instrument itself is almost always drafted as an on-demand guarantee — the issuing bank will usually pay out on a compliant demand without independently investigating whether the underlying default really occurred. The dispute over whether the call was justified happens afterwards, through the Contract's own mechanism, not before the bank pays.
That asymmetry is why the entitlement-and-notice conditions in Sub-Clause 4.2 matter so much on paper even though they do not stop the bank paying out in the moment. If the Employer calls the security for an amount it was not entitled to, Sub-Clause 4.2 requires the Employer to indemnify the Contractor for the amount wrongly drawn — the remedy for an unjustified call comes after the money has moved, not before.
Key Takeaway: The Employer can only call the Performance Security for a genuine entitlement under the Contract, and must first notify the Contractor of the default alleged. Because the guarantee is usually on-demand, the bank still pays first and the fight over whether the call was justified happens afterwards, backed by the Employer's indemnity obligation if it was wrong.
Release: When the Contractor Gets It Back
The Performance Security has to stay valid and enforceable for far longer than most Contractors expect when they first arrange it — through construction, through Taking-Over, and through the Defects Notification Period. The Employer must return it to the Contractor within 21 days after receiving a copy of the Performance Certificate, the certificate issued once outstanding work has been finished and defects have been remedied, near the very end of the Defects Notification Period.
That timing surprises Contractors who assume the security comes off their books once the Works are taken over. It does not. Taking-Over closes the construction phase; the Performance Certificate closes the whole contractual relationship, and only then does the 21-day return clock start. A bank facility carrying the security's cost is, realistically, a cost that runs for the full life of the project.
Key Takeaway: The Performance Security is not released at Taking-Over. It is returned within 21 days of the Performance Certificate, which comes near the end of the Defects Notification Period — so budget for the bank's fees over the full contract duration, not just the construction period.
Performance Security vs Advance Payment Guarantee vs Retention Money
These three all sound like the same kind of financial protection, and Contractors routinely mix them up when planning cash flow. They are not interchangeable:
- Performance Security (Sub-Clause 4.2) — an external bank or insurance instrument covering the Contractor's overall performance. Sized as a percentage of the Accepted Contract Amount. Delivered within 28 days of the Letter of Acceptance, returned within 21 days of the Performance Certificate.
- Advance Payment Guarantee (Sub-Clause 14.2) — also an external bank instrument, but it covers only the mobilisation advance. Its value shrinks as the advance is repaid through Interim Payment Certificates, and it is typically released mid-project, well before the Performance Certificate.
- Retention Money (Sub-Clause 14.9) — not a bank instrument at all. It is the Contractor's own money, deducted as a percentage from its Interim Payment Certificates, and usually released in two halves: part at Taking-Over, the balance at the end of the Defects Notification Period.
A Contractor can easily be carrying all three at once on a live project — paying bank fees on two guarantees while also having cash withheld from every certificate. Knowing which instrument covers which risk, and which deadline governs each one, is what keeps a release request from being sent to the wrong clause.
Key Takeaway: Performance Security backs overall performance; the Advance Payment Guarantee backs only the mobilisation advance; Retention Money is the Contractor's own cash held back, not a bank guarantee at all. Three different instruments, three different release triggers.
Frequently Asked Questions
Is the Performance Security the same thing as the Advance Payment Guarantee?
No. They secure different obligations. The Performance Security under Sub-Clause 4.2 secures the Contractor's overall performance of the whole contract, is usually a fixed percentage of the Accepted Contract Amount, and stays in place until the Performance Certificate is issued near the end of the Defects Notification Period. The Advance Payment Guarantee under Sub-Clause 14.2 secures repayment of the mobilisation advance only, shrinks as the advance is repaid, and is normally released mid-project once the advance is fully repaid.
Is the 28-day deadline to deliver the Performance Security the same as the 28-day notice deadline for claims?
No, and confusing them is a real risk precisely because both are 28 days. The Sub-Clause 4.2 deadline is for delivering the Performance Security to the Employer, counted from receiving the Letter of Acceptance — it is a contract-formation obligation, not a claim. The Sub-Clause 20.1 deadline is for serving a notice of claim, counted from awareness of a delay or cost event. They run from different trigger dates, for different purposes, and missing one has nothing to do with the other.
Can the Employer call the Performance Security for any reason?
No. Under Sub-Clause 4.2 the Employer may only claim under the Performance Security for amounts to which it is actually entitled under the Contract, and must first notify the Contractor of the nature of the default being claimed for. A call that is not backed by a genuine entitlement exposes the Employer to a claim for indemnity from the Contractor for the amount wrongly drawn.
When does the Contractor get the Performance Security back?
The Employer must return the Performance Security to the Contractor within 21 days after receiving a copy of the Performance Certificate. The Performance Certificate is issued near the very end of the Defects Notification Period, once outstanding work and defects have been completed and remedied, so the security stays in place for the life of the project, not just the construction phase.
Is Performance Security the same as Retention Money?
No. Retention Money is a percentage deducted from the Contractor's own Interim Payment Certificates and typically released half at Taking-Over and half at the end of the Defects Notification Period — it is the Contractor's own money being held back. The Performance Security is an external bank or insurance instrument the Contractor arranges and pays for separately, sized as a percentage of the Accepted Contract Amount. A Contractor on a tight cash-flow often carries both at once.
Authoritative Sources
This guide reflects the FIDIC Conditions of Contract and established practice around demand guarantees. For the primary materials, see:
- FIDIC Conditions of Contract — the official contract suite published by the International Federation of Consulting Engineers, which sets out the Sub-Clause 4.2 Performance Security provisions and the Sub-Clause 14.2 Advance Payment Guarantee it is often confused with.
- ICC Uniform Rules for Demand Guarantees (URDG 758) — the rules that commonly govern on-demand bank guarantees of the kind used as Performance Security, including how a demand is made and honoured.
About the Author
Muhammad M. Jiwani is a Project Director with 15 years' experience on major infrastructure and energy projects administered under FIDIC contracts. He writes from first-hand experience serving notices and managing contractual claims on live projects.