Legal contracting in English: pitfalls and best practices

I. Choosing the language: B2B vs. B2C context

In Belgium, the use of English in legal contracts is becoming increasingly common, particularly in business-to-business (B2B) transactions. This trend is driven by several practical considerations. In multilingual countries like Belgium (with Dutch, French, and German as official languages), English is often used as a neutral alternative to avoid favouring one local language over another. Moreover, English offers access to a rich body of established legal terminology and model clauses, especially in areas such as finance and technology—domains where Anglo-American legal systems have long influenced international practice. In this sense, the adoption of English reflects broader trends toward globalization, business efficiency, and the demand for clear, universally understood contract language.

The situation is different in a business-to-consumer (B2C) context. The appropriate choice of language may vary depending on the nature of the product or service delivered and the envisaged audience, but we typically still recommend drafting consumer contracts in one of Belgium’s official national languages. While consumer protection laws do not mandate a specific language, they do require that contractual information is presented in a clear and comprehensible manner. Although many Belgians have a strong command of English, when it comes to contracts, it is important to assess whether your average consumer is likely to fully understand the content. As a result, the best practice remains to use Dutch, French, or—less commonly—German, based on the linguistic region you are delivering the goods or services.

Furthermore, regardless of the B2B or B2C context, certain agreements must still be drafted in the local language. This requirement applies for instance to employment contracts or registered lease agreements. Even if both parties are fluent in English or operate in an international context, drafting these types of contracts in another language may result in the contract being considered null and void, or at least create evidentiary issues in the event of a dispute.

So, while English has an important role in Belgian legal contracting, especially in a B2B context, careful consideration of the legal context and audience remains essential—particularly when dealing with consumers.

II. Key challenges in using English-language contracts

The difficulty when using English is often the lack of knowledge about English legal concepts and the different use of it under Belgian law.

For instance, the concept of ‘gross negligence’ is interpreted differently under UK law compared to Belgian law. While both legal systems recognize the concept of gross negligence, Belgian law treats it as a distinct and structured category of fault (‘zware fout’/’faute grave’), whereas UK law uses it more flexibly and contextually. This could have implications particularly in limitation of liability clauses (See also articles 5.89 of the Belgian Civil Code and VI.63/1 of the Belgian Code of Economic Law). Hence, when applying English legal concepts in English language contracts, it needs to be clear for all parties how these need to be interpreted: whether the person negotiating the contract refers to the UK interpretation or to a specific Belgian law concept. In principle, the concept will be interpreted under Belgian law if such is made the governing law of the contract.

Other discussions can occur when using concepts such as ‘best efforts’; reasonable efforts’, ‘endeavours’, etc. Under Belgian law, a distinction is made between an obligation of result and an obligation of means. Using one or the other can have a significant impact upon proof of non-fulfilment of an obligation. To avoid legal uncertainty, it could be an option to change ‘best efforts’ explicitly referring to an obligation of result, or to include the Dutch/French translation between brackets: best efforts (‘resultaatsverbintenis’/’obligation de résultat’), whilst reasonable efforts (‘middelenverbintenis’/‘obligation de moyen’).
Furthermore, Anglo-Saxon contracts are typically more detailed and comprehensive than those governed by Belgian law. This is largely due to the relatively limited codification of contract law in common law systems. In Belgium, by contrast, contractual provisions are often supplemented by statutory rules, and judges interpret contracts within this legal framework rather than relying solely on precedent. As a result, Belgian contracts can be shorter and less exhaustive. Only where the parties intend to derogate from default legal provisions, specific clauses must be included.
A clear example is the doctrine of hardship (‘imprevisieleer’/ ‘la théorie de l'imprévision’), which allows a party to request renegotiation of the contract when an unforeseeable event causes such a serious imbalance that continued performance under the original terms becomes extremely burdensome. Article 5.74 of the Belgian Civil Code explicitly provides this right. Unless the contract states otherwise, this principle applies automatically. In contrast, under Anglo-Saxon law, such a mechanism must be expressly included in the contract to take effect. In Belgian contracts, it may on the other hand be advisable to expressly exclude the doctrine if the parties wish to avoid its application or specifically modify the conditions or consequences of the unforeseeability. Another illustration is the statutory interest applicable to B2B transactions under the Belgian Act of 2 August 2002 (as amended). Even if no interest clause is included, a default interest rate—currently 10.5% for Q2 2025—automatically applies in the event of late payment.
In addition, contracts governed by Anglo-Saxon law often contain phrases such as “such consent shall not be unreasonably withheld”. Under Belgian law, however, the overarching principle of good faith in the performance of contracts already implies a duty of reasonableness. As such, the inclusion of specific provisions to this effect might be unnecessary, since the legal framework inherently expects parties to act reasonably and fairly in the execution of their contractual obligations.

Another important consideration in legal drafting is the differing approach to contract interpretation between legal systems. Under Belgian law, in the event of a dispute, the judge will seek to determine and give effect to the common intent of the parties, even if that intent is not perfectly reflected in the wording of the contract. By contrast, in common law jurisdictions, courts generally adopt a more literal or textual approach, giving primary weight to the plain meaning of the contractual language. The intent of the parties is typically inferred from the text itself, and extrinsic evidence is used only in limited circumstances. These divergent interpretive methods mean that wording which appears clear in English may be understood differently when applied under Belgian law, potentially leading to unintended legal consequences.

III. Conclusion: the case for caution

While drafting agreements governed by Belgian law in English is increasingly common in international practice, it is not without risk. Legal concepts do not always translate seamlessly across legal systems, and terminology commonly used in Anglo-Saxon contracts may carry different interpretations—or no equivalent at all—under Belgian law. Moreover, Belgian courts interpret contracts through the lens of parties’ mutual intent and established legal principles, rather than relying solely on the literal meaning of the words. As a result, even well-drafted English clauses may give rise to ambiguity or unintended effects when applied in a Belgian legal context.

IV. Practical tips for drafting contracts in English under Belgian Law

We set out some tips to minimize legal uncertainty and ensure enforceability:
1. Avoid simply copying templates from the internet or reusing agreements drafted for other jurisdictions or contexts. Contract language must be tailored to the applicable legal framework—what works in a common law system may not align with Belgian legal principles.
2. When referring to specific Belgian legal concepts, consider adding the equivalent term in Dutch or French to avoid ambiguity. Examples:
- best efforts (‘middelenverbintenis‘/’obligation de moyens’);
- judicial reorganisation (‘gerechtelijke reorganisatie’/’réorganisation judiciaire’)
- pledge (‘pand’/’gage’)
- a power of attorney (‘lastgeving’/ ‘mandat’)
3. Translation tools such as DeepL can be useful, but they are not fully reliable for legal terminology. Nuanced or system-specific legal terms are often mistranslated or oversimplified, which can lead to confusion or legal risk.
4. Do not solely rely on AI tools for drafting or reviewing legal documents. While they can assist with structure or language suggestions, they do not replace legal expertise—especially in cross-jurisdictional matters where precision and contextual interpretation are key.

Legal contracting in English: pitfalls and best practices