Polymarket takes Dutch gambling fine to court as KSA pushes ahead with €420,000 penalty

Polymarket has filed an appeal in The Hague against a €420,000 penalty from the Dutch gambling authority, Kansspelautoriteit (KSA). For PSPs and payment teams, the useful bit is simple: the Netherlands is still treating prediction markets as gambling, and the regulator is willing to follow through even after the operator says it has blocked local access.

1. The KSA blacklisted Polymarket at the start of 2026 for offering unlicensed gambling services to Dutch consumers. It warned the platform’s parent company, Adventure One, that it would face financial consequences unless Polymarket blocked access in the Netherlands by 17 February.
2. Polymarket later complied with the order, but in May the KSA told Adventure One it would still proceed because Polymarket had officially withdrawn on 18 February. The authority published the formal notice in June and said it would move to recovery and enforcement actions because the penalty had not been paid.
3. Adventure One argued that it had already started working on the block on 18 February and that the testing phase still allowed access only because the full block was still being rolled out. The company said this was not negligence, but a technical feature of the rollout completed within the short grace period. The KSA rejected that explanation.
4. Polymarket is now challenging the fine in The Hague, according to FD. For payment providers, the practical signal is that Dutch enforcement is not just about access blocking; the regulator is also prepared to pursue monetary penalties and collection steps when it believes an operator has breached its rules.
5. The case sits inside a wider policy debate in the Netherlands and Europe. Dutch MP Iem Al Biyati proposed a separate framework for prediction markets, but State Secretary Claudia Van Bruggen turned it down after the KSA said these offers are gambling. Elsewhere in Europe, Gibraltar has adopted a dedicated regulatory framework for prediction markets, Malta has hinted at moving in that direction, and Kalshi said at the SBC Summit that it is in active talks with EU-level regulators including the European Securities and Markets Authority (ESMA).

Polymarket and Kalshi both came out of the US, where event contracts are regulated at the federal level by the Commodity Futures Trading Commission (CFTC) as financial instruments. That split treatment is exactly why prediction markets keep surfacing in payment and compliance discussions: one regulator calls it gambling, another calls it a financial product, and the acquiring stack has to decide which view matters today in the relevant jurisdiction.