Polymarket appeals €420,000 Dutch gambling authority penalty

Polymarket has launched a legal challenge in The Hague against a €420,000 (£365,000) penalty imposed by the Dutch gambling regulator, Kansspelautoriteit (KSA), according to SBC News.

The KSA blacklisted Polymarket at the start of 2026, ruling that the platform was offering unlicensed gambling services to consumers in the Netherlands. It ordered parent company Adventure One to block Dutch access by 17 February or face financial penalties.

Polymarket complied with the blocking order, but in May the KSA told Adventure One it would still pursue the penalty, on the grounds that Polymarket had only formally withdrawn from the Dutch market on 18 February, one day after the deadline.

The regulator made the notice public in June and said it would move to recovery and enforcement action after Adventure One failed to pay the fine.

Adventure One argued it had started work on the block on 18 February itself, and said a testing phase that still allowed access reflected technical limitations rather than any failure to act. The company stated that this was "not negligence, but a known feature of the technology, and that the measures have been implemented as quickly and carefully as possible within the short grace period."

The KSA rejected that explanation, prompting Polymarket to take the case to court, as first reported by Dutch outlet FD.

The dispute lands amid wider uncertainty over how prediction markets should be treated across Dutch and European politics. Dutch MP Iem Al Biyati had proposed a separate regulatory framework for prediction markets in the House of Representatives, but the motion was rejected by State Secretary Claudia Van Bruggen, who deferred to the KSA's position that such offers constitute gambling.

Most European regulators have so far kept prediction markets out, according to SBC News, though Gibraltar has introduced what it describes as the world's first dedicated regulatory framework for the sector, and Malta has signalled it may move in a similar direction. Kalshi has said at the SBC Summit that it is in active talks with EU-level bodies including the European Securities and Markets Authority.

In the United States, where both Polymarket and Kalshi originated, event contracts are regulated federally as financial instruments by the Commodity Futures and Trading Commission. That designation remains contested, with states including New York, Arizona, Massachusetts and Minnesota rejecting the financial-markets label in favour of treating the products as gambling.

The sector's standing with harm-reduction groups has also come under strain. Heather Maurer is to step down as Executive Director of the National Council on Problem Gambling on 16 October after ten months in the role, with neither she nor the NCPG giving a reason. Her departure follows a $2m partnership between the NCPG and Kalshi, after which the Ohio Casino Control Commission, the Nevada Council on Problem Gambling and the Michigan Gaming Control Board all cut ties with the NCPG.

A separate case involving a self-excluded US bettor who allegedly lost thousands of dollars on Kalshi has added to scrutiny of the platform's approach to problem gambling, according to SBC News.