The 28-day rule that costs contractors millions

What Sub-Clause 20.1 actually says

FIDIC Sub-Clause 20.1 (in the 1999 Red Book) reads, in the most relevant part:

"If the Contractor considers himself to be entitled to any extension of the Time for Completion and/or any additional payment, under any Clause of these Conditions or otherwise in connection with the Contract, the Contractor shall give notice to the Engineer, describing the event or circumstance giving rise to the claim. The notice shall be given as soon as practicable, and not later than 28 days after the Contractor became aware, or should have become aware, of the event or circumstance."

And then, the critical sentence: "If the Contractor fails to give notice of a claim within such period of 28 days, the Time for Completion shall not be extended, the Contractor shall not be entitled to additional payment, and the Employer shall be discharged from all liability in connection with the claim."

Discharged from all liability. Not reduced, not diminished, not subject to discretion. Extinguished. A contractor can have a valid entitlement worth hundreds of thousands of pounds, and lose it entirely because a notice arrived on day 29.

Why contractors miss it

The 28-day clock starts from when the contractor "became aware, or should have become aware" of the event. This is not always a single, obvious moment. A delay event is often a process — a drawing issue that begins as a query, evolves into a revised instruction, then crystallises as a programme impact over the course of several weeks. By the time it is clearly a claim event, the clock may already have been running for 21 days.

Construction projects also move fast. Site engineers are managing concrete pours, RFI (Request for Information) responses, subcontractor coordination, and daily programme pressure simultaneously. The email that triggered the 28-day clock arrived on a Tuesday afternoon and was actioned as a technical matter. Nobody flagged it as a claim event. Nobody started the clock. Three weeks later, the contracts manager picks it up — and has seven days to produce a formal notice.

In many cases, they do not make it. In others, they do not even know the clock was running.

What counts as a valid notice

The notice must be given to the Engineer (not the employer's commercial team, not by phone, not by a site diary entry). It must describe the event or circumstance giving rise to the claim. It does not need to quantify the claim at this stage — that comes later under Sub-Clause 20.1's further submission requirements. But it must clearly identify what happened and when.

An email that says "just to let you know, we think there may be a delay claim here" is probably insufficient. A letter that says "pursuant to Sub-Clause 20.1 of the Contract, we hereby give notice of our intention to claim an extension of time and additional cost arising from [specific event], which we became aware of on [date]" is a valid notice.

The format matters. The address matters. The timing matters. All of these are administrative tasks — and all of them can fall through the cracks when a project team is under pressure.

The FIDIC 2017 position

The 2017 FIDIC suite maintained the 28-day notice requirement but refined the consequences. Sub-Clause 20.2 of the 2017 Red Book still requires a 28-day notice, and still provides that failure to notify results in loss of entitlement. However, the Engineer is now obliged to respond to a late notice with a reasoned decision as to whether the claim is time-barred — it is not automatic. This provides marginally more protection, but the principle remains: notify within 28 days or risk losing everything.

How to protect yourself

The answer is systematic monitoring. Every communication, every instruction, every drawing revision, every RFI response needs to be reviewed for claim event potential at the point of receipt — not weeks later. The 28-day clock does not wait for the end of a busy period.

Practically, this means building a habit of contractual review into daily project management. Every incoming communication should be reviewed by someone with contractual awareness. Claim events should be logged on the day they are identified, not at the end of the week. Notices should be drafted and sent immediately, even before the full quantum is known.

Technology can support this process substantially. AI tools can monitor incoming communications for contractual trigger events and flag potential claim events the moment they arrive — reducing the risk that a delay event sits unrecognised in an email inbox while the 28-day clock runs down.

A final note

Missing a FIDIC notice deadline is not a sign of negligence. It is a sign that a professional was doing five things at once on a complex project and this one thing was not caught in time. It happens to experienced teams on well-managed projects.

The answer is not to tell contractors to be more careful. The answer is to build a system that catches it — because the project will always generate more work than one person can manage perfectly, and the contractual clock does not slow down to accommodate that reality.