Contracts teams who learned claims on the 1999 Red and Yellow Books tend to assume the 2017 suite is the same machine with more pages. The notice clock is the same. The procedure around it is not, and the differences are exactly where a team running both editions across a portfolio makes mistakes.
What stayed the same: the 28-day notice
Under Sub-Clause 20.1 of the 1999 forms, the Contractor must give notice of a claim not later than 28 days after becoming aware, or when it should have become aware, of the event or circumstance. Under Clause 20.2 of the 2017 forms the same 28-day period from awareness applies. Both are drafted as conditions precedent: miss the window and the entitlement is lost. The Privy Council confirmed the 1999 wording operates that way in Uniform Building Contractors Ltd v Water and Sewerage Authority of Trinidad and Tobago [2026] UKPC 2, and commentary on that judgment noted the 2017 clause, though slightly more flexible, is clearly a condition precedent too.
What changed
| Step | FIDIC 1999 (Sub-Clause 20.1) | FIDIC 2017 (Clauses 20.2 and 3.7) |
|---|---|---|
| Who claims under the clause | Contractor claims only; Employer claims sat in Sub-Clause 2.5 | Both Parties use the same claims procedure |
| Notice of claim | Within 28 days of awareness; time-barred if late | Within 28 days of awareness; time-barred if late, with a route for the Engineer to consider late notice if justified |
| Fully detailed claim | Within 42 days of awareness, or as agreed with the Engineer | Within 84 days of awareness, and the statement of contractual basis carries its own time-bar |
| Engineer's response | Within 42 days of the fully detailed claim, approval or disapproval with comments | Agreement or determination under Clause 3.7: 42 days to reach agreement, then 42 days to determine |
| Continuing effect | Interim claims at monthly intervals, final claim within 28 days of the end of the effects | Interim fully detailed claims monthly; final within 28 days of the end of the effects |
The 84-day window is not relief
The longest-lasting misunderstanding about 2017 is that the extension from 42 to 84 days makes the regime softer. It does not. The 2017 form attaches a time-bar to the statement of contractual basis inside the fully detailed claim, so there are now two deadlines with consequences rather than one. A team that files the short notice on day 27 and relaxes has 57 more days to get the contractual basis on paper, and then the second bar falls.
Clause 3.7: the determination step
The 1999 form asked the Engineer to respond with approval or disapproval and left the rest to the dispute clause. The 2017 form formalises what happens next. The Engineer consults with both Parties to try to reach agreement within a time limit, and if there is no agreement, makes a fair determination within a further limit. Both limits are 42 days by default. A determination that neither Party disputes with a notice of dissatisfaction within 28 days becomes final and binding. That is a third clock, and it is the one that most often surprises teams who came up on the 1999 books.
Particular Conditions change all of it
Everything above is the standard form. Gulf employers amend both editions heavily. Notice periods are shortened, condition-precedent language is added where the standard form has none, and records requirements are tightened. The correct question is never which edition, but what your contract says. Read the Particular Conditions against the standard clause line by line, and record the differences somewhere the whole team can see them.
What this means in practice
- Track three clocks on a 2017 project: 28-day notice, 84-day fully detailed claim, and the 42-plus-42 agreement or determination timeline.
- Do not treat the 84 days as slack. The statement of contractual basis has its own bar.
- On a portfolio with both editions, label each project's family explicitly and never let one project's deadlines be computed with another's rules.
- Read the Particular Conditions first. The standard form is the baseline you diff against, not the answer.
DraftMyEOT ships separate profiles for FIDIC 1999 and 2017, then verifies each against your uploaded Particular Conditions and shows the diff before any deadline is computed.
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This article is general information about how these contract mechanisms typically work. It is not legal advice, and it is not a substitute for review of your specific contract by a qualified professional.