What does good faith (redelijkheid en billijkheid) mean in Dutch contract law?

Dutch term: Redelijkheid en billijkheid | Legal basis: Article 6:248 of the Dutch Civil Code

Good faith (redelijkheid en billijkheid) is the overarching principle in Dutch contract law under article 6:248 of the Dutch Civil Code. It serves two functions simultaneously: it supplements contracts with obligations that follow from reasonableness and fairness (the supplementary effect, aanvullende werking), and it can limit or override contractual provisions whose application would be unacceptable in the circumstances (the derogatory effect, derogerende werking).

The supplementary effect means that parties are bound not only to what they have explicitly agreed, but also to what follows from the nature of the contract and from standards of reasonableness and fairness. Gaps in the contract are filled by what the parties could reasonably have intended.

The derogatory effect is more dramatic: a court can set aside even a clearly drafted contractual term if applying it in the specific circumstances would produce an outcome that is unacceptable by the standards of reasonableness and fairness. The threshold is high in commercial cases between professional parties, but the power is real and is exercised by Dutch courts in practice.

The concept has no direct equivalent in most common-law systems. English law has implied terms and unconscionability doctrines, but neither operates as broadly as Dutch redelijkheid en billijkheid. For international businesses contracting under Dutch law, understanding this principle is essential because it affects how contracts are drafted, interpreted and enforced.

Why it matters for international businesses

Exoneration clauses, penalty clauses and other aggressive provisions that would be enforceable as drafted in a common-law jurisdiction can be moderated or set aside under Dutch good faith. Equally, obligations that are not stated in the contract may be implied. See our Dutch contract law guide for the full framework or contact MAAK Advocaten for specific advice.