A contractor with a strong delay or variation claim can lose all of it by missing a single notice. In time bar claims construction contract Vietnam practice, the 28-day notice period in FIDIC-based contracts is the most common point on which well-founded claims fail, and employers and lenders are increasingly aware of it.
This article sets out how the time bar works in the FIDIC 1999 edition, how Vietnamese law interacts with it, and how to protect or resist a claim. The risk is especially acute on multi-package infrastructure, factory, energy and resort projects, where notices must be sent to the right party in a chain of subcontracts and approvals.
What a time bar does and why it matters on Vietnam projects
A time bar is a contractual condition that makes timely notice a precondition of entitlement. If the claimant misses the deadline, the claim is extinguished or reduced, however strong its merits. The clause is a risk-allocation tool: it lets the employer know its exposure early, investigate while evidence is fresh, and manage budget and lender reporting.
On projects in Vietnam the issue is sharpened by three practical factors. Site teams are often locally staffed while claims are drafted by offshore commercial teams, so the date of awareness is disputed. Instructions are frequently given orally or by informal messaging. And notices may be sent to the wrong person or address, which creates a second argument about validity on top of the first.
The FIDIC 1999 edition: the clock under Sub-Clause 20.1
This section is based on the FIDIC 1999 edition, as reflected in the Silver Book text. The Red and Yellow Books use the same Sub-Clause number and a materially similar claims procedure, with the Engineer acting in place of the Employer; check the exact wording of the edition you signed. The 2017 second edition has a different, more detailed claims procedure and is not analysed here.
The 28-day notice
Where the Contractor considers itself entitled to an extension of the Time for Completion and/or additional payment, under any Clause or otherwise in connection with the Contract, it must give notice describing the event or circumstance. The notice must 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.
The consequence is stated in the same Sub-Clause. If the notice is not given within the 28 days, the Time for Completion is not extended, the Contractor is not entitled to additional payment, and the Employer is discharged from all liability in connection with the claim.
Three points of interpretation follow:
- “Should have become aware” introduces an objective test. The clock can start before the contractor’s site manager actually notices a problem.
- “Event or circumstance” is not the same as the resulting delay. Time normally runs from the event, even if its full impact is not yet known.
- The notice is a gateway, not the claim. It needs to describe the event; the detailed submission follows later.
The rest of the procedure
After a valid notice, the Contractor must submit supporting particulars as relevant, and keep contemporary records to substantiate the claim. The Employer may monitor those records and instruct that further records be kept, without admitting liability.
A fully detailed claim, with full supporting particulars of the basis of the claim and of the time and money claimed, is due within 42 days of awareness, or within another period proposed by the Contractor and approved by the Employer. Where the event has a continuing effect, that claim is treated as interim, further interim claims follow at monthly intervals, and a final claim is due within 28 days after the end of the effects.
The Employer must respond within 42 days of receiving a claim or further particulars, with approval or with disapproval and detailed comments. It may request further particulars but must still respond on the principles of the claim. The matter is then agreed or determined under Sub-Clause 3.5. Under Sub-Clause 3.5 of the Silver Book text, each party must give effect to the determination unless the Contractor gives notice of dissatisfaction within 14 days; either party may then refer the dispute to the Dispute Adjudication Board.
A softer rule for later steps
The final paragraph of Sub-Clause 20.1 provides that if the Contractor fails to comply with the Sub-Clause or another Sub-Clause in relation to a claim, any extension of time or additional payment shall take account of the extent to which the failure prevented or prejudiced proper investigation, unless the claim is excluded under the second paragraph. In plain terms, the 28-day notice is an absolute gateway, while lateness at later stages is dealt with by proportionate reduction. Tribunals will often look closely at which of the two a late step falls into.
Holding a late notice, a disputed date of awareness or a claim you believe is out of time? IVLF Advisors can arrange a confidential preliminary review of the contract and correspondence under NDA, so that deadlines and options are mapped before the next step. We cannot guarantee outcomes.
Deadline map: from event to arbitration
The table below collects the key periods in the FIDIC 1999 edition (Silver Book text) and shows how quickly the position can be lost. Periods in the Particular Conditions of your contract override the general conditions.
| Step | Sub-Clause | Period | Consequence of default |
|---|---|---|---|
| Notice of Contractor’s claim | 20.1 | 28 days from awareness (or when it should have been aware) | No extension, no payment, Employer discharged |
| Fully detailed claim | 20.1 | 42 days from awareness, or as approved | Assessment reflects prejudice to investigation |
| Employer’s response | 20.1 | 42 days from receipt of claim | No forfeiture stated; matter proceeds to determination or dispute |
| Contractor’s dissatisfaction with a determination | 3.5 | 14 days from receipt | Determination takes effect |
| DAB decision | 20.4 | 84 days from reference | Either party may give notice of dissatisfaction |
| Notice of dissatisfaction with DAB | 20.4 | 28 days from decision | Decision becomes final and binding |
| Arbitration after dissatisfaction | 20.4, 20.5 | From the 56th day after notice, unless otherwise agreed | Arbitration may start without amicable settlement attempt |
Two features deserve emphasis. First, the Employer’s own claims under Sub-Clause 2.5 require notice “as soon as practicable” after awareness, without a 28-day cut-off, so the bar is asymmetrical. Second, Sub-Clause 14.14 limits the Employer’s liability after the final statement to amounts expressly included, subject to its exceptions, which is a further long-stop on late claims. Our article on payment and final account in Vietnam explains how the final statement fits with Vietnamese settlement rules.
Vietnamese law: written notice, statutory deadlines and limitation
A FIDIC time bar operates inside Vietnamese mandatory law when the contract is governed by it or performed in Vietnam. Vietnamese law does not replicate the 28-day mechanism, but it adds its own requirements and deadlines.
Writing and addressing requirements
Article 4 of Decree 210/2026/ND-CP, which replaced Decree 50/2021 with effect from 1 July 2026, requires proposals and requests to be in writing. Article 21 provides that a party that finds the other party has performed wrongly or failed to perform may make a claim, setting out the grounds and evidence and sending it to the proper transaction address.
If the claim is not resolved, the dispute proceeds under the contract and Article 17. Under Article 84(1) of the Construction Law No. 135/2025/QH15, amendments of contract content must be in writing. Informal channels are therefore a weak foundation for either a notice or a variation.
The seven-working-day reply on public and PPP projects
For public investment and PPP projects only, Article 21 of Decree 210/2026 requires the recipient of a claim to respond in writing within seven working days, accepting or refusing with reasons. Article 4 contains a similar seven-working-day reply obligation for requests. These periods do not apply to private projects, where the response period is whatever the parties agreed.
Statutory limitation is a separate layer
The contractual notice period is different from the statutory limitation period for bringing proceedings. As general background, the Civil Code 2015 applies a three-year limitation period for bringing a court claim in contract disputes, running from when the claimant knew or ought to have known its rights were infringed. This is background knowledge; how limitation is treated in arbitration depends on the chosen rules, for example those of VIAC.
The practical point is that the two layers operate cumulatively. A claim can be well inside the statutory period yet barred under Sub-Clause 20.1, and a claim that was notified in time still needs to be pursued before limitation expires.
Enforcing time bar claims construction contract Vietnam disputes in full
This is the question foreign contractors most often ask, and the honest answer is that it depends on the governing law, the forum and the facts. Freedom of contract supports enforcement; arguments against include good faith, waiver by the employer’s conduct, and the proportionality of forfeiture. We are not aware of a settled rule that would justify relying on non-enforcement, and we would not advise a client to do so. For contracts governed by foreign law, with arbitration seated abroad, the position depends on that law and the tribunal’s approach.
Practical protection for contractors in time bar claims construction contract Vietnam cases
A hypothetical illustration shows how the bar bites. A contractor on a private industrial project receives, on day 1, an oral instruction from the Employer’s Representative to relocate a utility line. Site staff comply and record it in a diary. The commercial team learns of it at the monthly meeting on day 40 and sends a notice on day 45.
The Employer rejects the claim as notified out of time. The contractor argues that awareness only arose on day 40, while the Employer points to the diary entry as showing that the contractor should have become aware on day 1. The dispute turns on the “should have become aware” limb, which is why site records and notice practice must be aligned.
The following steps assume a FIDIC-based contract but are sensible under most forms, and they apply equally when a lender’s engineer is reviewing time bar claims construction contract Vietnam exposure ahead of a drawdown.
- Build a notice calendar. Assign a named person to log every instruction, late drawing, access failure or change event on the day it occurs, with the date of awareness.
- Notify early and broadly. A short, factual notice that identifies the event and states that time and cost are claimed is better than a late detailed one. Over-notification is cheap; late notification is not.
- Follow the contract’s formalities. Use the address, language, format and delivery method stated in the contract. Keep proof of delivery. Check who is authorised to receive notices after any change of Employer’s Representative or Engineer.
- Do not rely on oral instructions. Confirm any oral instruction in writing straight away, referring to the Sub-Clause.
- Keep contemporary records. Notice preserves entitlement; records prove quantum. Daily diaries, programmes, correspondence and cost coding matter equally.
- Flow down the deadlines. Make sure subcontracts require notice early enough for the main contractor to meet its own 28 days.
Our guide to extension of time under Vietnamese construction contracts explains how the entitlement side works once notice is validly given.
Reading the Particular Conditions before the clock starts
Few Vietnamese projects use the General Conditions unamended. Particular Conditions commonly change the claims regime in ways that matter more than the headline 28 days. Check at least the following:
- whether the notice period has been shortened (for example to 14 days) or lengthened;
- whether notice must be sent to a named person, in a prescribed form or in Vietnamese as well as English;
- whether the time bar has been extended to the Employer’s own claims and to claims for Defects Notification Period extensions;
- whether the bar applies to additional payment only, or to time as well, since some bespoke contracts treat the two differently; and
- whether a failure to notify is expressed as a condition precedent, or merely as a factor in assessment.
Where the drafting is ambiguous, tribunals generally prefer clear words before accepting that a right has been forfeited. Do not assume ambiguity will help you; draft and administer the contract so that none arises.
Practical points for employers and lenders
An employer or lender should not treat the time bar as a technicality to be pleaded at the end. Four practical disciplines reduce risk.
- Respond properly and on time. The Sub-Clause expects a response within 42 days, and silence invites a dispute; on public and PPP projects the seven-working-day statutory reply also applies.
- Avoid conduct that undermines the bar. If the employer or its representative engages on the merits of a late claim without reserving its position, a tribunal may find waiver. Reserve rights expressly in correspondence.
- Review the Particular Conditions. Amendments to Sub-Clause 20.1 are common. Some narrow the bar, some lengthen it, and some add a condition that the notice be in a particular form.
- Report exposure to lenders. Lenders’ technical advisers should receive an up-to-date register of notices received and claims barred or under assessment, with reasons.
The employer’s position in time bar claims construction contract Vietnam disputes is strongest when it has administered the contract consistently. A tribunal is likely to be less receptive to a bar defence from an employer who has ignored the contract’s own procedural steps.
Time bar claims construction contract Vietnam across project types: infrastructure, industry, energy and real estate
A 28-day clock is the same length on a terminal package and on a hotel fit-out, but who must receive the notice and who notices the event first differ. The examples are hypothetical.
Infrastructure and transport
Expressway, rail-station and airport-terminal contracts are often State-funded and so often within the public-investment or PPP regime, although classification depends on funding source and is determined project by project. The seven-working-day reply rule discussed above applies on that basis only.
With multiple contractors on the planned North–South high-speed railway (about 1,541 km, Hanoi to Ho Chi Minh City, 15 provinces and cities), each section package would carry its own notice chain, and a notice sent to the wrong entity could be argued to be invalid. On an airport terminal such as phase 1 of Long Thành International Airport (commercial operation expected from 24 December 2026 per press reports), late-stage compressed schedules make events occur faster than claims teams can notice them.
Heavy industry and factories
Steel, petrochemical and cement plants and FDI factories are typically private, EPC-style, and often use the Silver Book. Commissioning and testing delays can start as site disputes and become claims only at completion, which is too late.
Renewable energy and power
For solar, wind and gas-to-power projects, delay by a grid operator or permit authority may be an Employer risk event; the notice should be sent immediately even if the cause is outside the Employer’s control. Offtake and financing documents may have their own claim deadlines that interact with the construction contract.
Real estate: resorts, hotels, urban areas and mixed-use
Resorts, hotels and mixed-use developments often involve many trade contractors and an operator’s brand standards. Design instructions given informally are a classic source of unnoticed claims. Party agreement governs.
| Sector | Notice risk | What to check |
|---|---|---|
| Expressway, rail, airport terminal | Multi-entity notice chain; approvals | Addressee; Decree 210 reply-time applicability |
| Factory, steel, cement | Late discovery at commissioning | Event log; Silver Book notice wording |
| Solar, wind, gas-to-power | Third-party and offtake deadlines | Parallel deadlines in other documents |
| Resort, hotel, mixed-use | Informal instructions | Written confirmation protocol |
Conclusion
The time bar is a risk allocation device, not a technicality. Under the FIDIC 1999 edition, a late notice can end a claim, and the Vietnamese legal overlay adds written-form requirements, statutory reply times on public projects and a separate limitation layer. Treat each deadline in the table as a project-control item rather than a legal footnote. A sensible first step is to audit your open claims and unnotified events against the contractual deadlines now, and to bring in counsel on any claim that is close to or beyond the 28-day mark.
Frequently Asked Questions
What is the notice period for claims under FIDIC 1999?
Under Sub-Clause 20.1 of the FIDIC 1999 text, the Contractor must give notice not later than 28 days after it became aware, or should have become aware, of the event. Particular Conditions may change this.
What happens if the contractor misses the 28 days?
The Time for Completion is not extended, no additional payment is due and the Employer is discharged from liability for the claim. Whether a Vietnamese tribunal would enforce this in full should be checked.
Is the Employer subject to the same time bar?
Not in the same way. In the Silver Book text, the Employer must give notice as soon as practicable after awareness under Sub-Clause 2.5, with no stated 28-day forfeiture.
Does Vietnamese limitation law replace the contractual notice period?
No. They are separate layers. The general three-year limitation period in the Civil Code is background knowledge that varies by forum; the contractual notice period operates independently.
Do the seven-working-day reply rules apply to private projects?
No. Decree 210/2026 sets that reply period for public investment and PPP projects only. Private contracts follow what the parties agreed.
Disclaimer: this article provides general information as of 22 October 2026 and is not legal advice on any specific matter. Contract wording, governing law and facts will change the analysis.
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