What is undue payment (onverschuldigde betaling) under Dutch law?

Dutch term: Onverschuldigde betaling | Legal basis: Article 6:203 BW

Undue payment (onverschuldigde betaling) under article 6:203 of the Dutch Civil Code creates a claim for repayment when a person has made a payment or performance without a legal basis. The recipient must return what was received, in kind where possible, in monetary equivalent where not.

The claim applies when payment was made by mistake, under a void contract, or after the legal basis for the payment has ceased to exist. It is distinct from unjust enrichment (article 6:212 BW), which has broader application but is limited to the lesser of the enrichment and impoverishment.

Why it matters for international businesses

In commercial practice, undue payment claims arise in refund situations, failed transactions, and when payments are made under contracts that are subsequently annulled or rescinded.