When is a lawyer liable for a professional error?

Introduction

A lawyer falls short in an attributable manner where, in handling a matter, the care is not exercised that may be expected of a reasonably competent and reasonably acting professional. That standard flows from the obligation of a good contractor (Section 7:401 DCC) and has been adopted as the starting point in the settled case law of the Supreme Court. The standard is simple to state and difficult to apply: the outcome depends each time on the concrete circumstances of the case.

For this contribution, civil decisions on the professional liability of the lawyer have been analysed, from district court judgments to judgments of the Supreme Court. Two lines emerge from those decisions. The professional errors that lead to liability are rarely the result of a mistaken point of law, but of organisational and communicative failings that have recurred for years: not recording agreements, not informing the client in good time, allowing a time limit to lapse, or failing to probe a file that called for more attention. Set against this is an equally firm second line: not every setback in a set of proceedings is a professional error. The courts draw a sharp boundary between suboptimal litigation and an attributable failure, and that boundary decides many cases. Both lines are worked out below by reference to a focused set of leading decisions.

Lawyer shares draft statement of grounds half an hour before filing and client loses EUR 49,475

A client conducts an inheritance dispute on appeal concerning an overallotment claim of just over EUR 419,000. His lawyer delivers the draft statement of grounds of appeal thirty minutes before the filing deadline expires, raises a hopeless jurisdictional incident, fails to include set-off items in the grounds, and wrongly informs the client that an oral hearing has been requested while the court has already set a date for judgment. The Gelderland District Court establishes three professional errors and orders the firm to pay compensation of EUR 49,475 (ECLI:NL:RBGEL:2025:2674).

The lawyer handling the matter could not demonstrate that the choice for a limited grounds strategy had been recorded in writing. The client had supplied documents concerning set-off items. Without a recorded counter-instruction, the defence that the client wished to raise grounds only on the security provision could not stand. The lesson that speaks from this case recurs throughout the case law analysed: it is the lawyer who must document the strategic choice and the client's instruction, not the client who must prove the contrary.

The engagement had formally been concluded with the firm, not with the lawyer handling the matter. The general terms and conditions excluded his personal liability on the basis of the engagement provisions, but not on the basis of tort (Section 6:162 DCC). Because the client was a consumer, the rule also applied that, where there is doubt about the interpretation of a term in general conditions, the interpretation most favourable to the consumer prevails (Section 6:238(2) DCC). Personal liability therefore remained open. The fact that an engagement was concluded with the firm thus offers the individual lawyer no automatic shelter from a claim.

The basic norm and the client's own responsibility

The legal relationship between lawyer and client is a contract for services carrying a best-efforts obligation, not an obligation to achieve a result. The Rotterdam District Court summarises the standard succinctly: there can only be an attributable failure where a reasonably competent and reasonably acting professional would, in the given circumstances, have acted differently or would or would not have given a particular piece of advice (ECLI:NL:RBROT:2024:2671 para. 4.4). Whether the duty of care has been met also depends on the circumstances of the case; in that regard significance may attach to the seriousness and extent of a risk, the likelihood of it materialising, and the degree to which the client was already aware of that risk (ECLI:NL:HR:2015:1406).

From that standard flows an own responsibility that reaches further than the literal engagement. The lawyer cannot confine himself to what the client asks of him, but must independently assess what matters for the case and act accordingly. The lawyer is dominus litis: he ultimately determines, after consultation with his client, what is and is not advanced. That leading role has a flip side. Where the lawyer conducts the direction, he can also be held to account for the consequences of a wrong directional choice.

That responsibility is bounded, however, by the client's responsibility to supply the facts relevant to his case. The Amsterdam Court of Appeal drew that sharply in a case in which a client reproached his lawyer for having raised the basis for full remuneration within the meaning of Section 7:411(2) DCC too late. The court held that the failure to mention facts and insights in the underlying matter does not constitute a breach of the norm, where it was for the client to bring those aspects forward in good time and it did not fall within the lawyer's duty of care to probe for them. The client had informed the lawyer only at a late stage about the true composition of the remuneration claimed, so that the lawyer simply did not have that crucial information. There was no professional error (ECLI:NL:GHAMS:2016:4105 paras 3.4 and 3.5). The duty of care therefore obliges the lawyer to think along independently, but not to guess at facts that the client keeps to himself.

Obligations that the courts consistently enforce

Within that basic norm a series of concrete obligations recurs time and again. Before the start of each separate set of proceedings, the lawyer must advise in writing on the prospects and risks, the evidence required and the anticipated costs. The Amsterdam District Court holds that insufficiently setting out the good and bad prospects of an appeal, and failing to warn that more evidence is needed, constitutes a professional error (ECLI:NL:RBAMS:2023:306). The underlying idea is that a client can only make an informed choice where he knows in advance what he is getting into. In line with this, the evidential strategy, which witnesses are deployed and in which proceedings, is an integral part of the professional performance of the task; an error in it is not merely a tactical choice but an attributable failure.

The lawyer also actively monitors limitation and procedural time limits for as long as the engagement has not been expressly terminated (ECLI:NL:GHAMS:2025:616). Allowing a limitation period or an appeal period to lapse is among the most common grounds of liability. The Supreme Court, without giving reasons (Section 81(1) RO), left in place the ruling that allowing a claim against a liable party to lapse can constitute a professional error (ECLI:NL:HR:2024:214). Furthermore, the lawyer must not allow his own financial interests to interfere with those of his client: advising in a situation of conflict of interest constitutes breach of contract towards the client and unlawful conduct towards the parties involved (ECLI:NL:GHDHA:2021:1385), and the disciplinary tribunal proceeded to strike off in a case of financial dependence through an affiliated company (ECLI:NL:TAHVD:2021:94). The client must not be unnecessarily exposed to foreseeable and avoidable litigation risks of which he is unaware, and whether strategy decisions taken without consulting the client constitute a professional error was left open by the court in one case; the claim failed for lack of a causal link (ECLI:NL:GHAMS:2023:516). Where the fee threatens to exceed the estimate given considerably, the lawyer must inform the client and consult on the continuation of the engagement (ECLI:NL:RBAMS:2026:2670 paras 4.9 and 4.12.3). And on the basis of Section 7:403 DCC he must answer, on the merits, concrete questions about the policy pursued, about the litigation strategy and the choice for or the omission of defences; the structural absence of such a response is an independent failure that is established as soon as it is documented.

The limits of the norm: not every setback is a professional error

Set against these obligations is a category of cases in which the lawyer is exonerated. Those cases are at least as instructive for practice, because they show where liability stops. In the decisions analysed, the same distinction recurs throughout: a professional error leading to civil liability arises less readily in the case of suboptimal conduct in proceedings than in the case of hard errors such as allowing time limits to expire. In the case of suboptimal litigation, the conduct must be clearly substandard (ECLI:NL:GHAMS:2016:4105 para. 3.4).

The Arnhem-Leeuwarden Court of Appeal applies this distinction in a divorce case. The client reproached his lawyer for having filed financial documents too late in the interim relief proceedings and for having failed to correct a remark of his at the hearing. Both complaints failed. From the mere circumstance that, in the client's view, the court's decision was wrong, it cannot be inferred that this was caused by the manner of litigation. Nor did the correction of a factual, self-evident statement by the client himself fall to the lawyer (ECLI:NL:GHARL:2022:2382 paras 2.12 to 2.16). An express and strongly worded advice against starting a poor-prospect set of proceedings over household costs also stood: a lawyer is free to accept an engagement or not, and the advice given that such proceedings are very difficult was not incorrect (paras 2.19 to 2.21).

The monitoring of time limits, however much it belongs to the core of the legal profession, also has its limits. The Rotterdam District Court ruled on a lawyer who had filed an application for leave to sell attached shares within a month after the judgment had become final and conclusive. The Hague District Court, however, interpreted the relevant forfeiture period of Section 715(3) DCCP differently, declared the client inadmissible and the attachments lapsed by operation of law. Even so, there was no professional error. A reasonably competent and reasonably acting lawyer may be expected to take account of various possible decisions by the court, but that duty of care does not go so far that he must take account of every possible outcome; in general he need not anticipate a decision with which he could not reasonably have had to reckon (ECLI:NL:RBROT:2024:2671 para. 4.5). The lawyer was entitled to rely on the text of the statute, which supported his reading, and did not have to err on the side of caution where statutory text, legislative history, literature and case law gave no cause for doubt (paras 4.11 and 4.12). That the lawyer had, moreover, advised the client after the disappointing decision to bring an appeal, which the client omitted to do, fell to the client's account (para. 4.13). The Hague Court of Appeal upheld that judgment (ECLI:NL:GHDHA:2025:2580). The boundary drawn here is sharp: a lawyer does not guarantee a correct outcome, but a defensible choice based on statute and case law at the moment he makes it.

Advising on rights, obligations and contractual forfeiture periods

Where the lawyer's freedom ends is at the duty to enable the client to decide on an informed basis. Where a lawyer advises a client in the context of a decision to be taken by that client, the duty of care entails that the lawyer enable the client to decide on a well-informed basis. A reasonably competent and reasonably acting professional may be expected to properly inform his client about his rights and obligations and to point out contractual forfeiture periods.

That proved fatal to the lawyer on one point in the same divorce case. Under his prenuptial agreement the client held a conversion right in respect of the pension of his former spouse, to be exercised by a single registered letter within six months of the dissolution of the marriage. The lawyer should have pointed the client to that forfeiture period, all the more so because the conversion right departed from the main rule of statutory pension equalisation and the client was six years older than his former spouse. Instead, the lawyer had repeatedly told the client that consent of the former spouse was required for conversion, which was incorrect. It was thereby established that the lawyer had not advised as could be expected of a reasonably competent and reasonably acting lawyer (ECLI:NL:GHARL:2022:2382 paras 2.24 to 2.28). The defence that the client did not want conversion anyway did not help: a person can only properly determine his wishes once he has been correctly informed about his rights and obligations (para. 2.26). This case shows that a single missed forfeiture period, in a file in which the lawyer acted correctly on other points, is sufficient for liability.

Taking stock in good time and interrupting limitation

The obligation to map out a client's rights becomes sharper as a limitation period approaches. The Hague District Court ruled, in a case concerning the winding-up of a terminated cohabitation, that a lawyer had committed a professional error by not taking stock in good time of whether his client had rights of reimbursement, as a result of which those claims became time-barred (ECLI:NL:RBDHA:2025:18157).

The decision is nuanced about the moment at which that duty arises. In response to the client's first, concrete question whether his former partner was entitled to half of his earnings, the lawyer was not yet required to make an extensive inventory: he had answered that concrete question and it was not asserted or apparent that the client wished further advice at that moment (para. 4.3). That changed when the matter developed further. At a meeting in October 2022 it emerged that there was a jointly owned home with considerable surplus value, and the lawyer had held the cohabitation agreement for months, in which nothing was arranged about rights of reimbursement. Precisely where nothing is arranged, it is important to enquire quickly about large payments, in view of the five-year limitation period (paras 4.5 and 4.7). By failing to do so, the lawyer did not do what could be expected of a reasonably competent and reasonably acting lawyer (para. 4.10). The defence that the surplus value would be divided in half anyway did not hold: precisely in order to be able to set off reimbursement claims against each party's half of the surplus value, it is necessary to map out those claims (para. 4.6).

The case also illustrates that the firm cannot, without more, rely on its own general conditions against a consumer. The forfeiture clause in the firm's conditions could not be invoked, because it had been insufficiently substantiated that those conditions formed part of this contract. No engagement confirmation had been sent, whereas that would have been appropriate after the meeting of October 2022, and the fact that conditions had been declared applicable in earlier engagements did not mean that they also applied to this new engagement (paras 4.14 to 4.16). For lawyers it follows from this that each engagement needs its own, recorded basis. The decision is an interlocutory judgment: the professional error is established, but the parties still had to comment on the extent of the loss.

Private client: additional obligations regarding costs

Where the client is a consumer, additional obligations regarding costs and information apply. Before concluding the engagement, the lawyer must, on the basis of Section 6:230l DCC and Section 6:230m DCC, communicate the total price or the method of calculation clearly and comprehensibly. The court reviews such consumer provisions of its own motion, even without the client invoking them. The Amsterdam Court of Appeal confirms that merely stating an hourly rate, without an indication of the total amount to be expected, does not satisfy the transparency requirement. Such a term is not automatically unfair, however: in that case the court held that the term was not unfair, and a price reduction of 25% followed for breach of the information duty, not from the unfairness test (ECLI:NL:GHAMS:2024:3269). A lawyer who insufficiently informs a private client about the costs to be expected thereby runs a double risk: annulment of the cost clause and an independent ground of liability alongside any professional-error claim.

Disciplinary law and civil liability: two frameworks of review

In support of a compensation claim, clients often point to a disciplinary ruling or to a decision of the Disputes Committee of the Legal Profession. That connection is less direct than it seems. The disciplinary tribunal and the civil court each apply a materially different framework of review. That an applicable norm for a professional group has been breached does not, without more, mean that the professional is also liable in civil law; what matters is the civil court's appraisal of the disciplinary tribunal's decision and of the other facts and circumstances that the civil court considers relevant (ECLI:NL:RBLIM:2022:9187 para. 4.2).

In that Limburg case, the Disputes Committee of the Legal Profession had ruled that standards of reasonableness and fairness precluded the collection of the balance of the fee notes, because advice had been given insufficiently structured and in writing. The client inferred from this that the lawyer had fallen short and claimed back just over EUR 54,000. The civil court did not follow this. The arbitral decision concerned only the collection of the balance of the invoices, not the greater part of the work performed and paid for, and the committee had had a less complete file. Assessed against the civil standard of the reasonably competent and reasonably acting professional, the complaints were insufficiently substantiated, and the mere failure to achieve the result desired by the client is insufficient to assume a failure (paras 4.4 to 4.12). The claims were dismissed. A disciplinary or arbitral rap on the knuckles is therefore an indication, not proof, of civil liability. What the tribunal itself assesses, and where it leaves the lawyer a discretion, is set out in the analysis of the disciplinary quality test.

Causation and loss assessment through loss of a chance

Once the professional error is established, the remaining question is what loss flows from it. That question can rarely be answered with certainty, because the outcome of the underlying proceedings has become hypothetical. The Supreme Court clarified on 16 January 2026 that the court must first seek to establish how the court in those hypothetical proceedings ought to have decided; only if that determination is not possible does an estimate of the chance come into play (ECLI:NL:HR:2026:53). Depending on the strength of the underlying file, that chance varies in the decisions analysed from around 20 per cent in the case of a weak defence (ECLI:NL:RBAMS:2025:2255) to 50 per cent where the facts are too uncertain to establish further (ECLI:NL:RBGEL:2025:2674, para. 3.84).

The assessment proceeds in two directions. Sometimes the court can directly establish that loss is plausible and refer the matter to the separate assessment-of-damages proceedings, as happened with the missed conversion of pension rights: the client would receive a lower pension for six years after his pensionable age (ECLI:NL:GHARL:2022:2382 para. 2.27). In other cases the assessment requires a further comparison between the situation with and without the error. In the Hague cohabitation case, it had to be examined how much the former partner would actually have paid in the hypothetical case, partly because she could have invoked reasonableness and fairness, and what costs the client would have incurred for that (ECLI:NL:RBDHA:2025:18157 paras 4.25 to 4.27). The doctrine of loss of a chance thus means that even a client with an inherently uncertain underlying case retains a real basis for compensation, provided the professional error and the connection with a lost chance are plausible.

What does this mean for the lawyer and his client?

For the lawyer, the case law analysed points in one direction: the majority of liability can be prevented with simple file discipline. Monitoring time limits, recording strategic choices and client instructions in writing, warning in good time where evidence is lacking or the budget threatens to be exceeded, and answering concrete accountability questions on the merits. These are not intellectual feats, but administrative and communicative routines. Where a defensible choice based on statute and case law turns out badly in hindsight, the lawyer in principle remains out of range; where an agreement or warning has not been recorded, the evidential risk shifts precisely towards him.

For the client it means that a disappointing outcome is not in itself a ground for a claim. What is decisive is whether the lawyer deviated from what a reasonably competent and reasonably acting professional would have done, whether the connection between that error and a lost chance is plausible, and whether the complaint was made in good time. A client who complains too late may lose his rights (Section 6:89 DCC), although that defence in practice has a high threshold because the courts take account of the difference in knowledge between client and lawyer (ECLI:NL:GHAMS:2025:1622). Where the conditions are met, the doctrine of loss of a chance offers a real basis for compensation even in an uncertain underlying case. A disciplinary ruling can support that claim, but does not replace the independent civil assessment.

Cited case law

Supreme Court

• Supreme Court 29 May 2015, ECLI:NL:HR:2015:1406
• Supreme Court 24 February 2024, ECLI:NL:HR:2024:214
• Supreme Court 16 January 2026, ECLI:NL:HR:2026:53

Courts of appeal and district courts

• Amsterdam Court of Appeal 11 October 2016, ECLI:NL:GHAMS:2016:4105
• The Hague Court of Appeal 6 July 2021, ECLI:NL:GHDHA:2021:1385
• Arnhem-Leeuwarden Court of Appeal 29 March 2022, ECLI:NL:GHARL:2022:2382
• Limburg District Court 16 November 2022, ECLI:NL:RBLIM:2022:9187
• Amsterdam District Court 26 January 2023, ECLI:NL:RBAMS:2023:306
• Amsterdam Court of Appeal 28 February 2023, ECLI:NL:GHAMS:2023:516
• Rotterdam District Court 20 March 2024, ECLI:NL:RBROT:2024:2671
• Amsterdam Court of Appeal 26 November 2024, ECLI:NL:GHAMS:2024:3269
• Amsterdam Court of Appeal 11 March 2025, ECLI:NL:GHAMS:2025:616
• Amsterdam District Court 9 April 2025, ECLI:NL:RBAMS:2025:2255
• Gelderland District Court 9 April 2025, ECLI:NL:RBGEL:2025:2674
• Amsterdam Court of Appeal 24 June 2025, ECLI:NL:GHAMS:2025:1622
• The Hague District Court 8 October 2025, ECLI:NL:RBDHA:2025:18157
• The Hague Court of Appeal 16 December 2025, ECLI:NL:GHDHA:2025:2580
• Amsterdam District Court 18 March 2026, ECLI:NL:RBAMS:2026:2670

Disciplinary tribunal

• Disciplinary Appeals Tribunal 2021, ECLI:NL:TAHVD:2021:94

Juriaan de Vries is a lawyer at Prime Law, specialising in corporate and commercial litigation. See the disclaimer.

See also

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• Professional liability: the standard and the defence
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• Lawyer's cost clause annulled: when is an hourly rate insufficient?