Template

Project Delay Letter to Client: A Sample You Can Adapt

Last updated July 2026 · 10 min read

"Just email the client directly" is easy to say and harder to get right. Most FIDIC guidance is written around a notice to the Engineer, but plenty of Contractors are on contracts with no Engineer in the middle. This guide gives you a project delay letter addressed the way your contract actually requires — straight to the Client or Employer — plus the one channel check that has to happen first.

Who "The Client" Actually Is, and Why the Addressee Matters

On a FIDIC Red Book or Yellow Book project, there is normally an independent Engineer sitting between the Contractor and the party paying for the Works. Notices go to the Engineer, who administers the contract on the Employer's behalf. In everyday site language, though, "the client" almost always means the Employer — the party the Contractor's agreement is actually with.

On a FIDIC Silver Book (EPC/Turnkey) project, there is no independent Engineer role at all. The Employer administers the contract directly, sometimes through its own representative. On that contract form, writing "to the client" is not a workaround — it is the correct and only channel.

The practical question is whether the contract's notices clause names the client as the valid recipient, or names the Engineer instead. Get that wrong and a well-written letter can still miss its legal purpose.

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Key Takeaway: "The client" usually means the Employer. On a Silver Book contract, the Employer is the correct and only address for notices. On a Red or Yellow Book contract, notices normally go to the Engineer, and a client letter is something separate. Check the contract before assuming either way.

What the Letter Must Contain

If this letter is doing the job of a formal notice, it needs these building blocks, addressed to the client instead of the Engineer:

An unambiguous heading — name it a notice of delay or claim so it can't be read as routine correspondence.
The cause clause and Sub-Clause 20.1 — the specific entitlement relied on, not a general reference to "the contract."
The trigger date — the day the Contractor became, or should have become, aware the event was causing delay. This is what the 28-day clock runs from.
What happened, where, and when — enough detail to identify the event without a full report.
The programme impact — which activity is affected and why it matters to the Time for Completion.
A reservation of rights — confirmation that particulars will follow within the contract period.

If the contract still has an independent Engineer and this letter is only a courtesy update, say so plainly at the top and confirm the formal notice has gone, or will go, to the Engineer separately. A client letter that reads like a notice but goes to the wrong contractual party can create confusion about whether the notice obligation was actually met.

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Key Takeaway: A heading that can't be mistaken for routine mail, the clause, the trigger date, what happened, the programme impact, and a reservation of rights — that's what makes this letter do a notice's job. If it is only a courtesy update, say so and confirm the real notice went to the correct party.

Project Delay Letter to Client — Template

Replace everything in square brackets with your own facts, then delete the brackets. Use this version where the Client/Employer is the correct contractual addressee — for example, on a Silver Book (EPC) project with no independent Engineer.

[Date] To: [Client/Employer's name and company] Project: [Project name and contract reference] Notice of Delay and Claim under Sub-Clause [X.X] and Sub-Clause 20.1 The Contractor gives notice under Sub-Clause [X.X] of the Conditions of Contract that an event has occurred which is delaying the Works. The Contractor became aware of this event on [trigger date]. What happened: [brief factual account — what occurred, its location on the Site, and the relevant dates]. This event is delaying the Works and is expected to affect the Time for Completion. [Brief statement of the effect — for example, the activity affected and why it is critical]. The Contractor reserves its right to an Extension of Time and to any associated Cost arising from this event. Detailed particulars will be submitted within [42] days in accordance with the Contract, or sooner if practicable. Yours faithfully, [Name] [Designation, for the Contractor]

Two warnings. First, "[42] days" is the FIDIC 1999 default for particulars; 2017 uses 84 days, and a bespoke contract may set its own figure — use whichever governs. Second, if the contract does have an Engineer and this is a separate update rather than the formal notice, drop the "Notice of Delay and Claim" heading and reservation-of-rights paragraph, and make sure the actual notice has gone, or is going, to the Engineer.

If drafting a fresh notice for every event feels slow, that is exactly the gap ChatNotice was built to close — describe the event in plain language and it drafts the notice with the correct clause and structure in place.

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Key Takeaway: One skeleton covers most delay types — swap the clause and the description. Use it as a formal notice only where the client is the correct contractual addressee; otherwise strip the notice language and send it as a separate update.

Worked Example: A Filled-In Letter to the Client

The template filled in for an EPC project with no independent Engineer, where an unforeseen utility clash has stopped excavation on a section of the Works:

3 July 2026 To: Ms H. Petrova, Project Sponsor, Northline Logistics Ltd Project: Northline Distribution Hub — EPC Contract NLH-2025-03 Notice of Delay and Claim under Sub-Clause 4.12 and Sub-Clause 20.1 The Contractor gives notice under Sub-Clause 4.12 of the Conditions of Contract that an event has occurred which is delaying the Works. The Contractor became aware of this event on 27 June 2026. On that date excavation for the eastern loading yard uncovered an active high-pressure gas main not shown on the tender utility drawings, requiring excavation in that area to stop pending relocation by the utility owner. This event is delaying the Works. The eastern loading yard excavation is on the critical path for the yard paving package, and work cannot resume until the utility is relocated. The Time for Completion is expected to be affected. The Contractor reserves its right to an Extension of Time and to any associated Cost arising from this event. Detailed particulars will be submitted within 42 days in accordance with the Contract, or sooner if practicable. Yours faithfully, D. Okonkwo Project Director, for the Contractor

Because this project has no independent Engineer, the Client is the correct and only recipient. The letter still does the same job a notice to an Engineer would: names the clause, fixes the awareness date, states the effect, and reserves the rights.

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Key Takeaway: On a no-Engineer contract, the client letter carries the full weight of the notice — there is no separate Engineer copy to fall back on, so it has to get the clause, date, and reservation of rights right the first time.

Confirm the Channel Before You Send

This is the one check that determines whether the letter above is a notice or just correspondence. Sub-Clause 1.3 of the Conditions of Contract sets out the valid method and address for notices. Read it before assuming who the letter should go to.

Red Book and Yellow Book (with an Engineer) — notices go to the Engineer. A letter addressed only to the client does not satisfy the notice obligation unless the notices clause says otherwise.
Silver Book (EPC/Turnkey, no Engineer) — notices go to the Employer directly. This is the scenario the template above is built for.
Bespoke or negotiated contracts — some route claims through a client-side representative instead of an Engineer. Check the actual clause; do not assume the standard form applies.

If in doubt, do both: the formal notice through the channel the notices clause names, and a shorter status letter to the client contact.

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Key Takeaway: Sub-Clause 1.3 decides who the valid recipient is — not habit, and not who happens to answer emails fastest. Red/Yellow Book routes through the Engineer; Silver Book routes through the Employer directly. When unsure, send the formal notice through the correct channel and a separate status update to the client.

Common Mistakes

Most project delay letters to a client run into trouble for a handful of avoidable reasons:

Addressing the notice to the wrong party. Sending a formal notice to the client when the notices clause names the Engineer, and vice versa.
Treating a status update as if it were a notice. A friendly heads-up with no clause reference and no awareness date protects nothing, even if the client acknowledges it.
Assuming every FIDIC contract has an Engineer. The Silver Book does not — check the contract form first.
No awareness date. Without a clear date, nobody can test the letter against the 28-day deadline.
Wrong particulars deadline. Writing the 28-day notice figure where the 42-day (or 84-day, under 2017) particulars period belongs.
Vague effect. Saying the programme is "affected" without naming the activity and why it is critical.

The cure for all six is deciding up front what the letter is for — a formal notice, a status update, or both — and drafting it to match.

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Key Takeaway: Most failures come from mismatched addressee and purpose. Decide what the letter is for before drafting it, and check Sub-Clause 1.3 rather than assuming.

Frequently Asked Questions

Who counts as "the client" in a FIDIC delay letter?

In FIDIC terms, "the client" almost always means the Employer — the party that appointed the Contractor and is paying for the Works. On a Red Book or Yellow Book project there is usually an independent Engineer between the Contractor and the Employer, and formal notices go to the Engineer. On a Silver Book (EPC/Turnkey) project there is no independent Engineer, so the Employer administers the contract directly and is the correct addressee for notices as well as informal updates.

Do I still need to notify the Engineer if I'm writing to the client?

If the contract has an Engineer, yes. Sub-Clause 1.3 sets out the valid channel for notices, and on most FIDIC forms that channel is the Engineer, not the Employer directly. A courtesy letter to the client does not replace a formal notice served on the wrong party. Check the notices clause first; only skip the Engineer if the contract genuinely has none, as under the Silver Book.

What deadline applies to a project delay letter to a client?

If the letter is serving as the formal notice of delay, the same deadlines apply regardless of who it is addressed to: 28 days from awareness for the notice under FIDIC 1999, and 42 days for the detailed particulars that follow (84 days under the FIDIC 2017 Second Edition). If the letter is a separate, informal status update rather than the notice itself, it carries no contractual deadline — but it also does not protect the Contractor's entitlement, so the formal notice still has to go out on time.

Is a project delay letter to a client legally the same as a notice of claim?

Only if it is drafted and addressed as one. A letter that simply informs the client the programme has slipped, without citing the contract clause, the awareness date, and a reservation of rights, is a status update, not a notice of claim, and will not protect an Extension of Time or Cost entitlement. To count as the formal notice, it needs the same building blocks as any FIDIC notice — just sent to the correct contractual addressee.

Authoritative Sources

This guide reflects the FIDIC Conditions of Contract and established construction-law authority:

FIDIC Conditions of Contract — the official contract suite published by the International Federation of Consulting Engineers, including the Silver Book (EPC/Turnkey) form referenced above and the Sub-Clause 20.1 claims procedure common to all three.
Obrascon Huarte Lain SA v HM Attorney General for Gibraltar — the leading authority on the validity and timing of a notice of claim under Clause 20.1.

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.

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