FIDIC Detailed Particulars: What to Submit Within 42 Days
This guide walks through the FIDIC 42-day detailed particulars under the 1999 Red Book — what they are, what they must contain, how to handle ongoing events, and why the 42-day submission is where strong claims are won and weak ones are quietly abandoned. If your project has live notices, this is the document that turns them into money.
What Are the 42-Day Particulars?
Under Clause 20.1 of the 1999 Red Book, within 42 days of becoming aware of the event giving rise to the claim, the Contractor must submit a "fully detailed claim" to the Engineer. This is the detailed particulars submission. It is where the Contractor actually sets out the case for time, money, or both.
The particulars are not an option. They are a contractual requirement. Failing to submit them — or submitting only a skeleton — gives the Engineer grounds to decline the claim, regardless of how strong the underlying merits are. Many contractors treat them as a "follow-up" to the notice, which is the wrong mental model. The notice is the summary. The particulars are the claim.
Think of the notice as the cover letter and the particulars as the application. Nobody expects the cover letter alone to win the job.
Key Takeaway: The 42-day particulars are the actual claim, not a follow-up. The notice preserves the right; the particulars exercise it. A valid notice followed by missing particulars is almost as damaging as no notice at all.
How They Differ From the Notice
The notice and the particulars serve different purposes and look different as documents:
- Notice — short (one to two pages), factual, submitted within 28 days. Announces that an event has occurred and a claim will follow.
- Particulars — detailed (tens to hundreds of pages), evidenced, submitted within 42 days. Makes the full case with numbers, analysis, and supporting documents.
The notice can be drafted in an afternoon. A proper particulars submission takes weeks of work — programme analysis, cost compilation, document assembly, expert input where relevant. Starting the particulars on day 40 guarantees a weak submission. Starting them on day 1, in parallel with the notice, produces a submission worth the Engineer's serious attention.
Key Takeaway: Notice is summary; particulars are substance. Start the particulars the day the notice goes out, not the day before the deadline. A two-week submission is always weaker than a six-week one.
What to Include in the Submission
A complete 42-day submission typically includes:
- Executive summary — a one-page overview of the event, entitlement, and quantum sought. Engineers appreciate this.
- Factual narrative — a clear, chronological account of the event with dates, locations, and personnel.
- Contractual basis — which clauses give the entitlement and why, analysed in detail.
- Programme and delay analysis — baseline programme, impact modelling, critical-path analysis, EoT calculation.
- Cost substantiation — detailed breakdown of the costs claimed, with supporting documents.
- Evidence bundle — correspondence, daily reports, photographs, test results, third-party records.
- Mitigation statement — what the Contractor did to reduce the impact.
- Quantified claim — specific days of EoT and/or amount of additional payment sought.
The submission should read as a self-contained case. The Engineer should be able to reach a determination without asking for further information. Every question that comes back from the Engineer is a signal that the submission left a gap — and while interaction is fine, too many gaps damage credibility.
Key Takeaway: A complete submission has executive summary, narrative, contractual basis, programme analysis, cost substantiation, evidence, mitigation, and quantum. Aim for a self-contained case the Engineer can determine without follow-up questions.
Delay Analysis: The Heart of It
For any claim seeking Extension of Time, the delay analysis is the core of the submission. Without a credible analysis linking the event to the critical path, even the best-documented narrative tends to fail.
A credible delay analysis includes:
- The accepted baseline programme — ideally the contract programme as updated at the time the event began.
- Identification of the delay event — start date, end date, nature, location in the programme.
- Methodology — the specific delay analysis method used (Time Impact Analysis, Windows, As-Planned vs As-Built, etc.) and why it is appropriate.
- Impact modelling — the programme with the delay inserted, showing the new critical path.
- Treatment of concurrency — identification of concurrent delays and the apportionment approach.
- Output — the specific EoT in calendar days, traceable to the programme analysis.
On significant claims, the delay analysis is often prepared by a specialist. An Engineer looking at a contested EoT claim will scrutinise the methodology as closely as the numbers. A thin analysis from an in-house planner is sometimes fine for small events; for a multi-million-dollar EoT, it is not.
Key Takeaway: Delay analysis is the core of any EoT claim. Pick a recognised method, use the accepted baseline, model the impact honestly (including concurrency), and present a clear output. On serious claims, use a specialist.
Cost Substantiation
For any claim seeking additional payment, the cost side must be substantiated with documents the Engineer can actually verify. "Trust us, it cost X" does not survive scrutiny.
A solid cost submission includes:
- Direct costs — labour, plant, materials, subcontractors — with timesheets, invoices, and plant records
- Site overheads — site management, facilities, utilities, on-site preliminaries for the extended period
- Head office overheads — calculated using an appropriate formula (Hudson, Emden, Eichleay) and properly substantiated
- Loss of productivity — where disruption is claimed, measured against baseline productivity with supporting records
- Finance costs — where the claim covers periods affected by delayed payment
- Profit — where allowed by the contract, at the contractual margin
Cost claims without supporting documents are the easiest for an Engineer to reduce or reject. A claim that includes its invoices, timesheets, and detailed calculations tends to attract reductions at the margin; a claim without them tends to attract reductions across the board.
Key Takeaway: Document every cost. Direct, site overheads, head office, productivity loss, finance, profit — each with calculations and supporting documents. Unsubstantiated costs invite across-the-board reductions.
Ongoing Events — The Monthly Update Rule
If the event is still affecting the Works at the 42-day mark, the Contractor cannot simply wait for the end of the event before submitting. The contract requires interim particulars at 42 days and monthly updates thereafter, with a final detailed claim within 42 days of the event's effects ending.
This is where most ongoing claims quietly fail. Teams submit the initial interim, then silence takes over for months. By the time the final claim lands, the Engineer has seen no updates for half a year, the records have gone cold, and arguments about when the effects "really" ended are wide open.
The discipline is simple: a monthly update for every live ongoing claim, even if it only says "the event continues, expected impact unchanged, further particulars to follow." Missing a month gives the Employer ammunition to argue the claim was abandoned or that the ongoing nature was less continuous than asserted.
Key Takeaway: Ongoing events need interim particulars at 42 days, monthly updates while the event continues, and a final claim within 42 days of effects ending. Missing months is how ongoing claims quietly die.
Common Mistakes in 42-Day Submissions
- Starting too late. Treating the 42-day deadline as the start date for drafting rather than the end date.
- Thin substantiation. Submitting a long narrative with minimal supporting evidence. Engineers read the evidence bundle, not the adjectives.
- No delay analysis. Claiming EoT without a credible programme analysis. Almost always fatal.
- Inconsistency with the notice. Particulars that contradict the awareness date, scope, or contractual basis of the notice. Credibility-destroying.
- Missing the interim deadline on ongoing events. Letting the event-in-progress claim slip past 42 days without any submission at all.
- No quantification. "Further details to follow" as the main body of a submission. The Engineer cannot determine a claim that has not been quantified.
- Over-claiming. Inflated numbers without supporting logic. Engineers reduce obviously inflated claims hard, even when the underlying entitlement is genuine.
Key Takeaway: The recurring killers are late starts, thin substantiation, missing delay analysis, inconsistency with the notice, missed interim deadlines, vague quantification, and over-claiming. A disciplined submission avoids all of these.
Frequently Asked Questions
What exactly are the FIDIC 42-day particulars?
The 42-day particulars are the detailed claim submission required under Clause 20.1 of the 1999 Red Book, following the initial 28-day notice. They set out the factual and contractual basis for the claim, the delay or disruption analysis, and the cost substantiation — the full case for the Engineer to consider.
Does the 42-day clock start from the notice or the event?
From the event. Both the 28-day and 42-day clocks run from the date the Contractor became aware of the event. The 42-day submission is due two weeks after the 28-day notice deadline, not two weeks after the notice was actually sent.
What happens if the event is still ongoing at day 42?
The Contractor must submit interim particulars at the 42-day mark, with a clear statement that the event is continuing. Monthly interim updates must then follow, and a final detailed claim within 42 days of the event's effects ending. Silence at 42 days is not an option.
How detailed should the particulars be?
Detailed enough that the Engineer can determine the claim on the merits without requesting further information. That usually means a narrative, contractual analysis, programme/delay analysis, cost substantiation with supporting documents, and a quantified claim. Thin submissions invite requests for clarification that eat into the Engineer's determination timeline.
Can the Contractor amend or supplement the particulars after submission?
Yes, within reason. If fresh evidence emerges or the quantum changes, supplementary submissions can be made. However, material changes to the legal or factual basis after the 42-day submission may weaken the claim or invite arguments that the initial submission was inadequate.