If work has not been carried out as agreed, record what was agreed, which elements deviate and what remedial work is needed. Report the defects in good time and, where necessary, give the contractor a reasonable opportunity to resolve the problem. Before bringing in a replacement, terminating the contract or withholding payment, have the applicable conditions assessed. A disappointing result is not necessarily a breach for which all costs can be recovered.
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Written by Onur Arslan, attorney at Arslan Advocaten. Registered in the specialisation register of the Netherlands Bar for employment law and personal injury.
This article is written from the perspective of the business client. If you are the contractor and your customer is withholding money, read customer refuses to pay because of defects. For a software implementation, there is a specific route in the case of a failed IT project.
Start with the agreed performance
Compare the agreement, quotation, drawings, order confirmation and relevant correspondence. What result was promised? What quality requirements applied? Were there dependencies, exclusions or work that you had to carry out yourself? In the case of services, an obligation to use best endeavours may call for a different assessment than a clearly agreed result.
Establish who the contracting party is. In a construction project, the client, main contractor, subcontractor and consultant may all be involved. The fact that you spoke to an employee or subcontractor does not automatically mean that you contracted directly with that person’s business.
Also check changes made during the work. A later request may affect the scope of the assignment, the price and the schedule. Keep messages about choices, additional work, changed materials, acceptance and completion. This prevents an agreed change from being wrongly presented as a defect, or a genuine deviation from being dismissed as additional work.
Draw up a usable list of defects
For each defect, describe the location, date of discovery, what was actually observed and the agreement from which the work deviates. Add photos, reports, test results or other documents. Distinguish between a visible deviation, a technical suspicion and established damage.
| Element | Example of useful documentation |
|---|---|
| Agreement | Part of the quotation or technical requirement, with date |
| Deviation | Specific location and description of what does not work |
| Evidence | Photo, measurement result, report or correspondence |
| Consequence | Repair needed, use impossible or additional costs |
| Request | Inspection, remediation plan or performance within an appropriate period |
For technically complex defects, an independent expert may be needed. Where appropriate, give the other party the opportunity to attend the investigation. A one-sided report can be useful, but the method of investigation and the opportunity to respond may give rise to dispute.
Limit acute damage where reasonably necessary. However, document the situation before intervening and, where sensible and possible, keep removed parts. Otherwise it may later be difficult to establish what was originally wrong.
Complaining and giving notice of default are separate steps
Article 6:89 of the Dutch Civil Code (BW) requires a complaint to be made within a reasonable time after a defect has been discovered or ought reasonably to have been discovered. What counts as timely depends on the circumstances. There is no fixed standard period for all business work. In the case of a sale, other provisions, including Article 7:23 of the Dutch Civil Code, may apply.
The complaint makes clear which defect you see in the performance. A notice of default has a different function: where required, it grants a final reasonable period for performance, so that default can arise if performance is not forthcoming. The letter must match the actual possibility of repair. Sometimes default follows from another statutory ground, or performance is impossible; the situation must then be assessed separately.
The statutory principles are set out in Book 6 of the Dutch Civil Code. In ECLI:NL:HR:2013:BY4600, the Supreme Court emphasised the importance of the circumstances for the duty to complain, including prejudice caused by the passage of time. So do not treat a template letter as a guarantee that every time limit is safe.
The practical details are explained under business notice of default. State in it the breach, the solution required, the time limit and the relevant earlier correspondence. Keep proof that the letter reached the correct party.
Must you allow the contractor to carry out repairs?
The contractor must often be given a reasonable opportunity to perform or to remedy defects. For construction contracts, Article 7:759 of the Dutch Civil Code contains a specific rule for defects after completion, with an exception where, in the circumstances, the client cannot be expected to have the contractor carry out the repair. The rules are set out in Book 7 of the Dutch Civil Code.
What is reasonable depends on factors such as urgency, the nature of the defect, previous repair attempts and the interests of the parties. A subjective lack of confidence is not always sufficient to hand the repair immediately to a third party. Conversely, not every dangerous or hopeless situation has to be continued indefinitely.
Make practical arrangements about access, inspection, scheduling and how to test whether the repair has succeeded. Keep the discussion about repairs separate from any additional heads of damage. An agreement to remedy a defect is not automatically a final settlement of all claims.
May you leave the invoice entirely unpaid?
Not every defect justifies withholding the entire payment. For suspension, the legal basis, the connection between the obligations and proportionality are relevant. Compare the disputed part with the overall performance and look at the contractual arrangements. A prohibition on suspension in terms and conditions also requires its own assessment.
Deducting an estimated item of damage from the invoice is something different from temporarily suspending payment. Set-off is subject to its own conditions. Read the explanation on suspending work or payment and setting off business invoices.
Do not leave a debt collection letter unanswered. Describe your specific defence and enclose the relevant file. The fact that the contractor demands payment does not end your substantive defence; equally, the fact that you complain does not mean the payment claim automatically disappears.
Replacement, termination and damages
Engaging another contractor may become necessary in practice, but the costs are not automatically fully recoverable. Examine whether the original party has had an appropriate opportunity to repair, whether default is required and what damage was caused by the breach. Keep quotations and invoices and choose a reasonable solution.
Termination under Article 6:265 of the Dutch Civil Code requires an assessment of the breach and its significance. Where necessary, the other party must be in default. Partial termination may work out differently from terminating the entire agreement. Obligations to undo performance and the value of performance already received may also play a role.
For damages, factors such as attributability, causal link, the extent of the damage and any limitations must be examined. Loss of turnover is not the same as loss of profit. Your own calculation without underlying figures is often insufficient. Check any limitation of liability and possible insurance cover, but do not assume that a single clause decides every consequence.
Proceedings turn on specific items
In ECLI:NL:GHAMS:2025:1516, a main contractor and a subcontractor were in dispute about work, additional work, invoices and damage. Each of the various elements had to be assessed on the basis of the agreements and the evidence. A general reference to poor workmanship does not replace that substantiation.
Organise your file, therefore, by claim and defence. What are you asking to be repaid, what repair do you want and what damage do you claim? Which amounts remain outstanding on the other side? A court may deal with a counterclaim that cannot be established sufficiently easily differently from the main claim. A litigation strategy must take both sides into account.
Arslan Advocaten can assess the documents and next steps through its corporate law practice. Include your list of defects, the agreement, the payment status and the next deadline. Discuss the costs of legal assistance and any technical investigation in advance.
Frequently asked questions
Can I engage another contractor immediately?
That depends on the situation. Assess the possibility of repair, the urgency and the applicable conditions before you seek to recover the costs from the original party.
Does completion mean I can no longer do anything?
Not automatically. The nature of the defect, the arrangements made, the applicable rules and the time of discovery all play a role. Report a discovered defect promptly and specifically.
Is a notice of default always required?
No. Default can sometimes arise in other ways, and different principles apply to certain forms of impossibility. Have the correct route assessed; do not send a standard letter blindly.
Can I claim all the business losses I have suffered?
Not without further assessment. The legal basis, evidence, causation, mitigation of loss and liability arrangements determine which damage may qualify for compensation.
Sources and legal basis
- Amsterdam Court of Appeal, 10 June 2025, on invoices, additional work and evidence in subcontracting (ECLI:NL:GHAMS:2025:1516).
- Supreme Court, 8 February 2013, on the duty to complain and the circumstances of the case (ECLI:NL:HR:2013:BY4600).
- Dutch Civil Code, Book 6 (law of obligations).
- Dutch Civil Code, Book 7 (specific contracts).
Corporate law at Arslan Advocaten. This article is revised when the law changes. Last updated: 19 September 2026. General information is not legal advice about your own situation.
